Search Result for "teratogen": 
Wordnet 3.0

NOUN (1)

1. any agent that interferes with normal embryonic development: alcohol or thalidomide or X-rays or rubella are examples; 



WordNet (r) 3.0 (2006):

teratogen
    n 1: any agent that interferes with normal embryonic
         development: alcohol or thalidomide or X-rays or rubella
         are examples