aculeus vs pricker

aculeus and pricker both are nouns.

Word	Noun	Adjective	Verb	Adverb
aculeus	Yes	No	No	No
pricker	Yes	No	No	No

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

Other hyponyms of aculeus include prickle, spikelet, spine, sticker, thorn.

aculeus (noun)	pricker (noun)
a sharp-pointed process especially a sting of a hymenopterous insect	an awl for making small holes for brads or small screws
a stiff sharp-pointed plant process	a small sharp-pointed tip resembling a spike on a stem or leaf