The Collaborative International Dictionary of English v.0.48:

Boyhood \Boy"hood\, n. [Boy + -hood.]
   The state of being a boy; the time during which one is a boy.
   --Hood.
   [1913 Webster]

WordNet (r) 3.0 (2006):

boyhood
    n 1: the childhood of a boy

Moby Thesaurus II by Grady Ward, 1.0:

20 Moby Thesaurus words for "boyhood":
   babyhood, childhood, childkind, children, girlhood, kids,
   little kids, maidenhead, maidenhood, new generation, pre-teens,
   rising generation, small fry, subteens, tots, young, young blood,
   young fry, young people, youth