an offensive formation with the tailback behind the fullback and the fullback behind the quarterback
I formation in American English
(ai)
noun
American Football
an offensive alignment in which the backs are positioned in line directly behind the quarterback
Word origin
[1950–55]This word is first recorded in the period 1950–55. Other words that entered Englishat around the same time include: action painting, drip-dry, point spread, point-of-sale, wiretap