Search Result for "rest mass":
Wordnet 3.0

NOUN (1)

1. (physics) the mass of a body as measured when the body is at rest relative to an observer, an inherent property of the body; 



WordNet (r) 3.0 (2006):

rest mass
    n 1: (physics) the mass of a body as measured when the body is
         at rest relative to an observer, an inherent property of
         the body