The Collaborative International Dictionary of English v.0.48:
Unapt \Un*apt"\, a.
1. Inapt; slow; dull. --Bacon.
[1913 Webster]
2. Unsuitable; unfit; inappropriate. --Macaulay.
[1913 Webster]
3. Not accustomed and not likely; not disposed.
[1913 Webster]
I am a soldier and unapt to weep. --Shak.
[1913 Webster] -- Un*apt"ly, adv. -- Un*apt"ness, n.
[1913 Webster]
Moby Thesaurus II by Grady Ward, 1.0:
65 Moby Thesaurus words for "unapt":
artless, half-assed, ill-adapted, ill-assorted, ill-chosen,
ill-fitted, ill-matched, ill-sorted, ill-suited, ill-timed,
improper, inadept, inadmissible, inapplicable, inapposite,
inappropriate, inapt, inattentive, inefficient, inept, inexpert,
infelicitous, irrelevant, mal a propos, maladjusted, malapropos,
mediocre, misjoined, mismatched, mismated, misplaced,
out of character, out of joint, out of keeping, out of line,
out of place, out of proportion, out of season, out of time,
out of tune, pedestrian, poor, skill-less, thoughtless, unadapted,
unbecoming, unbefitting, undeft, undexterous, undextrous, undue,
unfacile, unfit, unfitted, unfitting, unhandy, unintelligent,
unproficient, unqualified, unseasonable, unseemly, unskillful,
unsuitable, unsuited, untimely