bunt vs headbutt

bunt is a noun but headbutt is not a noun.

Word	Noun	Adjective	Verb	Adverb
bunt	Yes	No	Yes	No
headbutt	No	No	Yes	No

As verbs, headbutt is a hyponym of bunt; that is, headbutt is a word with a more specific, narrower meaning than bunt:

bunt (noun)	headbutt (noun)
(baseball) the act of hitting a baseball or softball lightly by holding the bat in a stationary position rather than swinging it
fungus that destroys kernels of wheat by replacing them with greasy masses of smelly spores
similar to Tilletia caries
disease of wheat characterized by replacement of the grains with greasy masses of smelly smut spores

bunt (verb)	headbutt (verb)
to strike, thrust or shove against	butt with the head
hit a ball in such a way so as to make it go a short distance