Astute, a. — Webster enters it under “astute”
Etymology: [L. astutus, fr. astus craft, cunning; perh. cognate with E. acute.]
Critically discerning; sagacious; shrewd; subtle; crafty.
Syn. -- Keen; eagle-eyed; penetrating; skilled; discriminating; cunning; sagacious; subtle; wily; crafty. As*tute"ly, adv. -- As*tute"ness, n.
Shades of meaning
Fernald lists astuteness only as an antonym, under idiocy.
He lists it without comment; the entries above explain its neighbors.
Synonyms
none given