Wordnet 3.0
NOUN (1)
1.
a wrestling hold in which the opponent's head is locked between the crook of your elbow and the side of your body;
The Collaborative International Dictionary of English v.0.48:
headlock \head"lock`\ (Sport), n.
A wrestling hold in which the opponent's head is locked
between the crook of your elbow and the side of your body.
[WordNet 1.5]
WordNet (r) 3.0 (2006):
headlock
n 1: a wrestling hold in which the opponent's head is locked
between the crook of your elbow and the side of your body