The Oxford Thesaurus An A-Z Dictionary of Synonyms - knowing adj.

1) conspiratorial or conspiratory, secret, private; significant, meaningful, eloquent, expressive; shrewd, canny, artful, sly, wily, crafty: She gave him a knowing wink. 2) wise, clever, shrewd, (well-) informed, knowledgeable or knowledgable, aware, expert, qualified, astute, perceptive, intelligent, sagacious: Harold is quite knowing about horses, why not ask him?