Source : Webster's Revised Unabridged Dictionary (1913)

Cubby \Cub"by\ (k?b"b?), Cubbyhole \Cub"by*hole`\ (-h?l`), n.
   [See {Cub} a stall.]
   A snug or confined place.

Source : WordNet®

cubbyhole
     n 1: a small compartment [syn: {pigeonhole}]
     2: a small secluded room [syn: {cubby}, {snuggery}, {snug}]