A Running Back Defense Against Tacklers

This page is the CodyCross answer for the clue below from Past and Present Tech, Group 1460, Puzzle 5 (Artificial Intelligence).

Question is: A Running Back Defense Against Tacklers

and the answer is: STIFFARM

Word Meaning:

STIFF — (of an object) Rigid; hard to bend; inflexible.

Definitions from Wiktionary.