headlock

from 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

from 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]