I think it might be an allusion to the phrase “imitation is the sincerest form of flattery”, as to butter (usually though not always with up), means to flatter. I’m not a fan, though
Many thanks for your super quick reply. You are right, I think. Doesn't feel as if it is the right part of speech though. I'd have imitation or imitatively.
Yes, and besides it is in a book so I can check the answer.
Most of the time I understand the answers even if I can't figure them out initially but for some clues I don't get the references but am getting better.
I think the books would be much better if they had a quarter the number of crosswords but with detailed explanations of the answers.
The superstars have enough on their plate with the various dailies so are unlikely to buy the books.