pubic louse vs crab louse

pubic louse and crab louse both are nouns.

Word	Noun	Adjective	Verb	Adverb
pubic louse	Yes	No	No	No
crab louse	Yes	No	No	No

As nouns, pubic louse and crab louse are synonyms defined as:

pubic louse and crab louse: a louse that infests the pubic region of the human body

Other synonyms of pubic louse include crab, Phthirius pubis.

pubic louse (noun)	crab louse (noun)
a louse that infests the pubic region of the human body	a louse that infests the pubic region of the human body