The Collaborative International Dictionary of English v.0.48:

Hooky \Hook"y\ (h[oo^]k"[y^]), a.
   Full of hooks; pertaining to hooks.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hooky \Hook"y\ (h[oo^]k"[y^]), n. [Written also hookey.] [Cf.
   Hook, v. t., 3.]
   A word used only in the expression to play hooky, to be
   truant, to run away; -- used mostly of youths absent from
   school without a valid reason and without the knowledge of
   their parents. Also (figuratively and jocosely), to be absent
   from duty for frivolous reasons.
   [Webster 1913 Suppl. +PJC]

         This talk about boys . . . playing ball, and "hooky,"
         and marbles, was all moonshine.          --F. Hopkinson
                                                  Smith.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

hooky
    n 1: failure to attend (especially school) [syn: truancy,
         hooky]