The Collins Concise Dictionary
Last updated: 17.12.19
Briefly, this edition has over 1.6 million words of text, more than 1,500 additional words and senses, most important current meanings first, usage guidance on disputed points, gives special attention to science and technology.
This book must the most referred to item in my library. Despite its now 13 year service (July 2002), it is still up-to-date for general usage. It will be with a heavy heart that I will eventually have to replace it. Even writing this anecdote, I was obliged to refer to it!