The Collaborative International Dictionary of English v.0.48:

Cranky \Crank"y\ (-?), a.
   1. Full of spirit; crank.
      [1913 Webster]

   2. Addicted to crotchets and whims; unreasonable in opinions;
      crotchety. [Colloq.]
      [1913 Webster]

   3. Unsteady; easy to upset; crank.
      [1913 Webster]

WordNet (r) 3.0 (2006):

cranky
    adj 1: (used of boats) inclined to heel over easily under sail
           [syn: crank, cranky, tender, tippy]
    2: easily irritated or annoyed; "an incorrigibly fractious young
       man"; "not the least nettlesome of his countrymen" [syn:
       cranky, fractious, irritable, nettlesome, peevish,
       peckish, pettish, petulant, scratchy, testy,
       tetchy, techy]