Wordnet 3.0
NOUN (1)
1. 
 an arm exercise performed lying face to the floor and pushing the body up and down with the arms; 
[syn: pushup, press-up]
WordNet (r) 3.0 (2006):
pushup
    n 1: an arm exercise performed lying face to the floor and
         pushing the body up and down with the arms [syn: pushup,
         press-up]