grump vs hothead

grump and hothead both are nouns.

Word	Noun	Adjective	Verb	Adverb
grump	Yes	No	No	No
hothead	Yes	No	No	No

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

Other hyponyms of grump include crab, crabby person, fire-eater, misanthrope, misanthropist.

grump (noun)	hothead (noun)
a bad-tempered person	a reckless impetuous irresponsible person
	a belligerent grouch