Wordnet 3.0
ADJECTIVE (1)
1. 
 (of meat) full of sinews; 
 especially impossible to chew; 
[syn: fibrous, sinewy, stringy, unchewable]
WordNet (r) 3.0 (2006):
unchewable
    adj 1: (of meat) full of sinews; especially impossible to chew
           [syn: fibrous, sinewy, stringy, unchewable]