nailhead vs boss

nailhead and boss both are nouns.

Word	Noun	Adjective	Verb	Adverb
nailhead	Yes	No	No	No
boss	Yes	Yes	Yes	No

As nouns, boss is a hypernym of nailhead; that is, boss is a word with a broader meaning than nailhead:

Other hypernyms of nailhead include knob.

nailhead (noun)	boss (noun)
flattened boss on the end of nail opposite to the point	a circular rounded projection or protuberance
something resembling the head of a nail that is used as an ornamental device	a person responsible for hiring workers
	a person who exercises control over workers
	a leader in a political party who controls votes and dictates appointments
	a person who exercises control and makes decisions

nailhead (adjective)	boss (adjective)
	exceptionally good

nailhead (verb)	boss (verb)
	raise in a relief