Real Dictionary

full nelson in American English
a hold in which both arms are placed under the opponent's armpits from behind with the hands pressed against the back of the opponent's neck
noun: a hold in which a wrestler, from behind the opponent, passes each arm under the corresponding arm of the opponent and locks the arms at the fingers or wrists on the back of the opponent's neck

full nelson in British English
noun: a wrestling hold, illegal in amateur wrestling, in which a wrestler places both arms under an opponent's arms from behind and exerts pressure with both palms on the back of the neck