Source : Webster's Revised Unabridged Dictionary (1913)

Crabby \Crab"by\ (-b[y^]), a.
   Crabbed; difficult, or perplexing. ``Persius is crabby,
   because ancient.'' --Marston.

Source : WordNet®

crabby
     adj : perversely irritable [syn: {crabbed}, {cross}, {fussy}, {grouchy},
            {grumpy}, {bad-tempered}, {ill-tempered}]
     [also: {crabbiest}, {crabbier}]