I found this to be at the easier end of the Jumbo scale and completed it over two sessions. There were two answers I didn’t know, one perhaps obscure and the other an awkward 8-letter word for a part of the body more usually referred to with a simple 5-letter word.
As usual definitions are underlined in bold italics, {deletions and substitutions are in curly brackets} and [anagrinds, containment, reversal and other indicators in square ones]. “Aural wordplay” is in quotation marks. I now use a tilde sign ~ to indicate an insertion point in containment clues. I usually omit all reference to juxtaposition indicators unless there is a specific point that requires clarification.
 Across |
|
|---|---|
| 1 | Crazed gang’s boss made good, finally (9) |
| POSSESSED – POSSE’S (gang’s), the {bos}S + {mad}E + {goo}D [finally] | |
| 6 | A locum tenens principally reads out systems of names (13) |
| NOMENCLATURES – Anagram [out] of A LOCUM TENENS R{eads}[principally] | |
| 13 | Former local representative concerned with one who raised Cain (5) |
| REEVE – RE (concerned with), EVE (one who raised Cain – son of Adam and Eve). There’s a Reeve’s Tale in Chaucer’s Canterbury Tales. | |
| 14 | Gold, extravagantly artisanal objects from down under (11) |
| AUSTRALIANA – AU (gold) anagram [extravagantly] of ARTISANAL | |
| 15 | Unsuccessful candidate somewhat irresolutely making a comeback (5) |
| LOSER – Hidden [somewhat[ and reversed [making a comeback] in {ir}RESOL{utely} | |
| 16 | I’m thrashing all over the place — very frightening (11) |
| NIGHTMARISH – Anagram [all over the place] of I’M THRASHING | |
| 17 | Change of direction inspires a French non-profit organisation (6,5) |
| CREDIT UNION – Anagram [change] of DIRECTION contains [inspires] UN (‘a’ in French) | |
| 18 | You shouldn’t have repeatedly run around knocking (3-1-3) |
| RAT-A-TAT – TA + TA + TA (‘you shouldn’t have’ repeatedly) + R (run) reversed [around] | |
| 20 | Quietly set aside bulb (7) |
| SHALLOT – SH (quietly), ALLOT (set aside) | |
| 21 | Spot politicians involved in grand act of perjury (7) |
| GLIMPSE – MPS (politicians) contained by [involved in] G (grand) + LI~E (act of perjury) | |
| 23 | That’s funny … promising crooners butchered series of numbers (8,11) |
| HARMONIC PROGRESSION – HA (that’s funny), anagram [butchered] of PROMISING CROONERS. Mathematics: a sequence of quantities whose reciprocals are in arithmetical progression (e.g. 1, 1/3, 1/5, 1/7, etc). I knew the term from music where it has a more specialised meaning. | |
| 27 | Food prices periodically dropped (3) |
| PIE – P{r}I{c}E{s} [periodically dropped] | |
| 28 | Ways to embrace love and compassion (6) |
| PATHOS – PATH~S (ways) containing [to embrace] O (love) | |
| 29 | Tree next to a lake in the mountains (6) |
| ALPINE – A, L (lake), PINE (tree) | |
| 31 | Boats in which Sydneysiders can have beers? (9) |
| SCHOONERS – The cryptic hint refers to a large glass from which Australians drink beer, as do Americans, Canadians and New Zealanders, according to Collins. In England it’s a large glass used for sherry – or was at one time. | |
| 34 | How things may come through the post? (2,7) |
| EX OFFICIO – Cryptic. Describes a benefit received as the result of one’s status or position. | |
| 35 | Commercial introducing Clio possibly provided some laughs (6) |
| AMUSED – A~D (commercial) containing [introducing] MUSE (Clio possibly) | |
| 36 | Bar before long is accommodating more or less everybody (6) |
| SALOON – S~OON (before long) contains [is accommodating] AL{l} (everybody) [more or less] | |
| 39 | Light breeze over valley (3) |
| RIA – AIR (light breeze) reversed [over]. A long, narrow inlet formed by the partial submergence of a river valley. | |
| 40 | Nefarious activity began in kindergarten, strangely (8,3,8) |
| BREAKING AND ENTERING – Anagram [strangely] of BEGAN IN KINDERGARTEN | |
| 42 | Official charge follows this significant fine ultimately (7) |
| STEWARD – {thi}S + {significan}T + {fin}E [ultimately], WARD (charge) | |
| 43 | Very big and small parts of a pinball table (7) |
| BUMPERS – BUMPER (very big), S (small} | |
| 45 | Vehicle that is on left of street with the most traffic? (7) |
| BUSIEST – BUS (vehicle), IE (that is), ST{street}. ‘On left of’ indicates placement. | |
| 47 | Former writer desperate to claim trade union disbursement (11) |
| EXPENDITURE – EX (former), PEN (writer), DI~RE (desperate) containing [to claim] TU (trade union) | |
| 49 | Early development of bug originally impacting people (11) |
| GERMINATION – GERM (bug), I{mpacting} [originally] NATION (people) | |
| 51 | Plate traditionally including fish (5) |
| TETRA – Hidden in [including] {pla}TE TRA{ditionally}. A small tropical variety of freshwater fish. | |
| 52 | Right structural unit housing books, computers, etc (11) |
| ENTITLEMENT – E~LEMENT (structural unit) containing [housing] NT (books) + IT (computers, etc) | |
| 53 | Tabloid lying about New York prosecutor and Irish police officer (5) |
| GARDA – RAG (tabloid) reversed [lying about], DA (New York prosecutor) | |
| 54 | Talks vacuously about stopping opportunities for scoring points (13) |
| CONVERSATIONS – A{bou}T [vacuously] contained by [stopping] CONVERS~IONS (opportunities for scoring points – rugby etc) | |
| 55 | Complex data view capturing large shift in public opinion (5,4) |
| TIDAL WAVE – Anagram [complex] of DATA VIEW containing [capturing] L (large) | |
| Down |
|
|---|---|
| 1 | Stand firm with co-director? (11) |
| PARTNERSHIP – Two meanings. ODE: stand – in cricket, another term for partnership: ‘they shared a second-wicket stand of 135‘. |
|
| 2 | Cunning, extremely spiritual cardinal (7) |
| SLEIGHT – S{piritua}L [ extremely], EIGHT (cardinal) | |
| 3 | Consistent time for the 100m, perhaps (5) |
| EVENT – EVEN (consistent), T (time) | |
| 4 | Taint of guilt besetting each top naval bigwig (3,7) |
| SEA CAPTAIN – S~TAIN (taint of guilt) containing [besetting] EA (each) + CAP (top). I don’t think of a sea captain as much of a bigwig; I was expecting something more in the realms of Admiral of the Fleet. | |
| 5 | Brush aside senior cop’s bad shot (7) |
| DISMISS – DI’S (senior cop’s), MISS (bad shot). Nor is DI a particularly senior rank in the police. | |
| 6 | Charlotte’s place adjacent to Virginia? (5,8) |
| NORTH CAROLINA – Mildly cryptic. Charlotte is the largest city in North Carolina to which the state of Virginia is adjacent. | |
| 7 | Spy caper almost broken by copper focusing on the tiniest details (9) |
| MOLECULAR – MOLE (spy) ~ LAR{k} (caper) [almost] containing [broken by] CU (copper) | |
| 8 | Close relatives live in comfortable home (7) |
| NEAREST – ARE (live) contained by [in] NE~ST (comfortable home) | |
| 9 | Influential figure in heavy metal initially is noticeably gentle, not heavy (7,5) |
| LEADING LIGHT – LEAD (heavy metal), I{s} + N{oticeably} + G{entle} [initially], LIGHT (not heavy) | |
| 10 | Human being’s terrible ill nature (9) |
| TELLURIAN – Anagram [terrible] of ILL NATURE. An inhabitant of the earth. NHO this word that’s making its debut here today. |
|
| 11 | Inspired poet seen in Paris, historically (5) |
| RISHI – Hidden [seen in] {Pa}RIS HI{storically}. We’ve become used to ‘rishi’ as a Hindu sage but as Collins confirms it previously meant a poet. Quite how ‘inspired’ fits in with this I don’t know. | |
| 12 | Irregularity of line taken out of choke point (11) |
| STRANGENESS – STRANG{l}E (choke) [line taken out], NESS (point) | |
| 19 | Stylish person, gathering endless looks, became popular (4,3) |
| TOOK OFF – T~OFF (stylish person) containing [gathering] {l}OOK{s} [endless] | |
| 22 | Hot meats go with a so-so Mexican chilli in the end (9) |
| PEPPERONI – PEP (go), PER (a), {so-s}O + {Mexica}N + {chill}I [in the end] | |
| 24 | Underlying reason to be frugal with booze (9) |
| RATIONALE – RATION ALE (be frugal with booze) | |
| 25 | Painter about to fill in survey, certainly (7) |
| POLLOCK – C (about) contained by [to fill in] POLL (survey) + O~K (certainly) | |
| 26 | Postpone financial outlay outside America (7) |
| SUSPEND – S~PEND (financial outlay) containing [outside] US (America) | |
| 30 | Shot that can’t be taken in the dark? (8,5) |
| EDUCATED GUESS – Cryptic | |
| 32 | Wild animals working long periods around river (7) |
| ONAGERS – ON (working), AGE~S (long periods) containing [around] R (river) | |
| 33 | Drinks in club consumed by prison officers (12) |
| SCREWDRIVERS – DRIVER (club – golf) contained [consumed] by SCREW~S (prison officers) | |
| 34 | Secret coup arranged to entrap one Brexiteer? (11) |
| EUROSCEPTIC – Anagram [arranged] of SECRET COUP containing [to entrap] I (one) | |
| 37 | Flyer nearly beginning to tumble during strong wind (11) |
| NIGHTINGALE – NIGH (nearly), T{umble} [beginning to…], IN (during] GALE (strong wind) | |
| 38 | Naked obedientiary in disarray, drunk (10) |
| INEBRIATED – Anagram [in disarray] of {o}BEDIENTIAR{y} [naked]. An obedientiary is the holder of any monastic office under the superior. | |
| 40 | Part of the head requiring type of strapped support as a precaution (9) |
| BRAINCASE – BRA (type of strapped support), IN CASE (as a precaution). More usually known simply as the skull. | |
| 41 | Deputy — increasingly insensitive — also yelled out (6,3) |
| NUMBER TWO – NUMBER (increasingly insensitive), aural wordplay [yelled out]:TWO / “too” (also) | |
| 43 | One tweeting obscene tirades is tactless, first and foremost (4,3) |
| BLUE TIT – BLUE (obscene). T{irades} + I{s}} + T{actless} [first and foremost] | |
| 44 | Southern artist upset fellow artist (7) |
| SARGENT – S (Southern), RA (artist) reversed [upset], GENT (fellow) | |
| 46 | Country’s victories regularly overlooked in time (7) |
| ERITREA – {v}I{c}T{o}R{i}E{s} [regularly overlooked] contained by [in] ER~A (time) | |
| 48 | Attach grips to mountaineering kit (5) |
| PITON – PI~N (attach) contains [grips] TO | |
| 50 | Support raised to bolster an investor (5) |
| ANGEL – AN, then LEG (support) reversed [raised] | |
DNK HARMONIC PROGRESSION, obedientiary, the poet meaning of RISHI. Is a toff stylish?
All the usual dictionaries mention well- or smartly dressed. Collins under American English has ‘Brit informal – a stylishly dressed, fashionable person’. What may confuse the issue is that the term toff is also used derogatorily for someone putting on airs and graces.