Search Result for "neutron": 
Wordnet 3.0

NOUN (1)

1. an elementary particle with 0 charge and mass about equal to a proton; enters into the structure of the atomic nucleus; 



WordNet (r) 3.0 (2006):

neutron
    n 1: an elementary particle with 0 charge and mass about equal
         to a proton; enters into the structure of the atomic
         nucleus