Once more, you can do free searches of Collins English Dictionary at the Collins web-site:
http://www.collinslanguage.com/
This is useful for the Times puzzle, as Collins is one of its two reference dictionaries. There do however seem to be some limitations – proper nouns like London or Churchill are not included in the search, and nor are phrases like “bad egg” (though it does get a mention under ‘bad’), and ‘egg’ has 5 senses here, compared to 9 in the 1991 printed version. You can pay for a ‘Pro’ version of this search, and it seems that you also get access to this service if you buy the printed version.
The other reference dictionary used by the Times is the Concise Oxford. This can’t be searched online, but its “little brother”, the Compact Oxford, can – at http://www.askoxford.com/dictionaries/?view=uk
1) Free to all. I think this is the one PB describes. It doesn’t find London or Churchill.
2) Available to buyers of the 9th edition printed version. This will find London and Churchill (not Sir Winston, but the two rivers of that name in Canada).
3) The Pro version to which you have to subscribe (£14.99 p.a.). Said to contain dictionary, thesaurus, biographies, fuzzy searches and just about everything under the sun.
I have had (2) for some time but rarely use it because it offers nothing more than the printed version and access to it is via an extremely secure and therefore easily forgettable password with no facility to change it to something more user-friendly. Collins inform me that this facility will be added at some stage but it doesn’t appear to have been included in their latest revamp.