Tailback

An offensive player who runs with the football.
Found on http://qhsfbclub.tripod.com/glossary.html

tailback

player position on offense farthest ('deepest') back, except in kicking formations. Also often referred to as the running back, particularly in a one-back offense.
Found on http://www.instantactionsports.com/sportsbook/arena-football/arena-football

Tailback

The running back deepest from the offensive line. Usually the team
Found on http://www.footballoutsiders.com/info/glossary_general
No exact match found