closer vs slammer

closer and slammer both are nouns.

Word	Noun	Adjective	Verb	Adverb
closer	Yes	No	No	Yes
slammer	Yes	No	No	No

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

closer (noun)	slammer (noun)
(baseball) a relief pitcher who can protect a lead in the last inning or two of the game	a correctional institution used to detain persons who are in the lawful custody of the government (either accused persons awaiting trial or convicted persons serving a sentence)
a person who closes something	a person who closes things violently

closer (adverb)	slammer (adverb)
(comparative of `near' or `close') within a shorter distance