Wiktionary
astutest
a. (en-superlative of: astute)
Usage examples of "astutest".
He had, in his prime, been one of the astutest skimmers of the Law of his generation.
He was, although he gave little sign of it, one of the astutest lawyers in Scotland.
This man, apparently so foolishly good-natured, simple, and absent-minded, could guess all the cunning of a prison wag, unmask the astutest street huzzy, and subdue a scoundrel.