WordWeb Online

1. Lacking grace in movement or posture
   "a clunky lad with long ungainly legs";
   - gawky, clumsy, ungainly, unwieldy, klutzy [N. Amer, informal]
    
2. Not elegant or graceful in expression
   - awkward, clumsy, cumbersome, inapt, inept, ill-chosen
    
3. Making a clunking sound

Derived forms: clunkier, clunkiest

See also: audible, awkward, hearable, infelicitous