WordWeb Online

1. Turned or twisted toward one side
   "a...youth with a gorgeous red necktie all wonky";
   - askew, awry, cockeyed, lopsided, skew-whiff [Brit]
    
2. Inclined to shake as from weakness or defect
   "the bridge still stands though one of the arches is wonky";
   - rickety, shaky, wobbly

Derived forms: wonkiest, wonkier

See also: crooked, unstable