Wordnet 3.0
NOUN (1)
1. 
 ratio of the hypotenuse to the opposite side of a right-angled triangle; 
[syn: cosecant, cosec]
WordNet (r) 3.0 (2006):
cosec
    n 1: ratio of the hypotenuse to the opposite side of a right-
         angled triangle [syn: cosecant, cosec]