steel guitar vs guitar

steel guitar and guitar both are nouns.

Word	Noun	Adjective	Verb	Adverb
steel guitar	Yes	No	No	No
guitar	Yes	No	No	No

As nouns, guitar is a hypernym of steel guitar; that is, guitar is a word with a broader meaning than steel guitar:

steel guitar: guitar whose steel strings are twanged while being pressed with a movable steel bar for a glissando effect
guitar: a stringed instrument usually having six strings; played by strumming or plucking

steel guitar (noun)	guitar (noun)
guitar whose steel strings are twanged while being pressed with a movable steel bar for a glissando effect	a stringed instrument usually having six strings; played by strumming or plucking