lineman vs tackle

lineman and tackle both are nouns.

Word	Noun	Adjective	Verb	Adverb
lineman	Yes	No	No	No
tackle	Yes	No	Yes	No

As nouns, tackle is a hyponym of lineman; that is, tackle is a word with a more specific, narrower meaning than lineman:

lineman: (American football) the position of a player on a football team who is stationed on the line of scrimmage
tackle: (American football) a position on the line of scrimmage, typically opposite one of the offensive guards

Other hyponyms of lineman include center, centre, guard, end.

As nouns, tackle is a hyponym of lineman; that is, tackle is a word with a more specific, narrower meaning than lineman:

lineman: one of the players on the line of scrimmage
tackle: the person who plays offensive or defensive tackle on a football team

Other hyponyms of lineman include center, centre, snapper, end, guard.

lineman (noun)	tackle (noun)
(American football) the position of a player on a football team who is stationed on the line of scrimmage	(American football) grasping an opposing player with the intention of stopping by throwing to the ground
one of the players on the line of scrimmage	(American football) a position on the line of scrimmage, typically opposite one of the offensive guards
a person who installs or repairs electrical or telephone lines	gear consisting of ropes etc. supporting a ship's masts and sails
the surveyor who marks positions with a range pole	gear used in fishing
	the person who plays offensive or defensive tackle on a football team

lineman (verb)	tackle (verb)
	seize and throw down an opponent player, who usually carries the ball
	put a harness
	accept as a challenge