IPA: //ˈhæf.bæk//
KK: /ˈhæfˌbæk/
A player in football or other sports who is positioned behind the line of scrimmage or forward line, often responsible for running with the ball or passing it.
The halfback made a great run down the field, helping the team score a touchdown.
Halfback → The word is formed from "half" (from Old English "healf", meaning part of a whole) and "back" (from Old English "bæc", meaning the rear or back part). The term "halfback" refers to a player in football who plays a position that is neither a fullback nor a quarterback, typically positioned in the middle of the backfield.
Think of 'half' meaning part of a whole and 'back' referring to the rear position — a halfback is a player positioned in the middle of the backfield.