Search Result for "pheromone": 
Wordnet 3.0

NOUN (1)

1. a chemical substance secreted externally by some animals (especially insects) that influences the physiology or behavior of other animals of the same species; 



WordNet (r) 3.0 (2006):

pheromone
    n 1: a chemical substance secreted externally by some animals
         (especially insects) that influences the physiology or
         behavior of other animals of the same species