WordNet sense 1 (difficult to handle or manage especially because of shape):

ungainly, bunglesome

WordNet sense 2 (difficult to use or handle or manage because of size or weight or shape):

unmanageable, unwieldy

WordNet sense 3 (showing lack of skill or aptitude):

bungling, incompetent, fumbling

WordNet sense 4 (not having or showing or requiring special skill or proficiency):

unskilled

WordNet sense 5 (lacking grace in movement or posture):

clunky, gawky

WordNet sense 6 (lacking grace or skill in manner or movement or performance):

awkward

WordNet sense 7 (not elegant or graceful in expression):

cumbersome, inapt, inept, ill-chosen

WordNet sense 8 (not appropriate in application; defective):

infelicitous