The Collaborative International Dictionary of English v.0.48:

life-size \life"-size`\, life-sized
\life"-sized`\(l[imac]f"s[imac]z`), a.
   Of full size; of the natural size; of the same size as an
   original; as, a life-size sculpture; a life-size portrait of
   the general.
   [1913 Webster]

WordNet (r) 3.0 (2006):

lifesize
    adj 1: being of the same size as an original; "a life-size
           sculpture" [syn: life-size, lifesize, life-sized,
           full-size]