HALFBACK
halfback
(noun) (American football) an offensive back usually positioned behind the quarterback and to the side of the fullback
halfback
(noun) (football) the running back who plays the offensive halfback position
Source: WordNet® 3.1
Etymology
Noun
halfback (plural halfbacks)
(field sports) Any of various positions on the field of play between the forwards and the fullbacks.
(field sports) A player who occupies one of these positions.
(American football) An offensive back whose primary jobs are to carry the ball on running plays and to serve as a receiver or blocker on passing plays.
(Canadian football) A defensive back whose primary jobs are to cover the slotback on passing plays and prevent running plays from going to the outside.
(field hockey) A player in the halfback position, with both offensive and defensive roles.
(Australian rules football) One of three players (the centre halfback and two halfback flankers) on the line between the centre line and the fullback line.
(rugby) The player who feeds the ball into the scrum, and receives the ball as it emerges from the back of the scrum.
Verb
halfback (third-person singular simple present halfbacks, present participle halfbacking, simple past and past participle halfbacked)
To play in the position of halfback.
Source: Wiktionary