fullback vs football

fullback and football both are nouns.

Word	Noun	Adjective	Verb	Adverb
fullback	Yes	No	Yes	No
football	Yes	No	No	No

fullback (noun)	football (noun)
(American football) the position of a back on a football team, generally larger in size than halfbacks	any of various games played with a ball (round or oval) in which two teams try to kick or carry or propel the ball into each other's goal
(football) the running back who plays the fullback position on the offensive team	the inflated oblong ball used in playing American football

fullback (verb)	football (verb)
play the fullback