cunning
adj.adj. showing cleverness and skill in achieving your goals, often by being tricky or secretive. You use it to describe someone who is smart but maybe a little sneaky.
adj. characterized by skillful cleverness, often implying deceit or subtlety in achieving an end. Typically used attributively or predicatively.
The cunning fox hid from the hunter.
Her cunning plan to surprise him worked perfectly.
The cunning politician avoided the direct question, weaving a complex answer that satisfied no one but himself.
From Middle English cunning, kunning, konnyng, alteration of earlier Middle English cunninde, kunnende, cunnand, from Old English cunnende, present participle of cunnan (“to know how to, be able to”), equivalent to con + -ing. Cognate with Scots cunnand (“cunning”), German könnend (“able to do”), Icelandic kunnandi (“cunning”). More at con, can.
From Middle English cunning, kunnyng, partially from Old English *cunning (verbal noun), from Old English cunnan (“to know how to, be able to”); partially from Old English cunnung (“knowledge, trial, probation, experience, contact, carnal knowledge”), from cunnian (“to search into, try, test, seek for, explore, investigate, experience, have experience of, to make trial of, know”), equivalent to con + -ing.