crab vs genus Phthirius

crab and genus Phthirius both are nouns.

Word	Noun	Adjective	Verb	Adverb
crab	Yes	No	Yes	No
genus Phthirius	Yes	No	No	No

crab (noun)	genus Phthirius (noun)
a stroke of the oar that either misses the water or digs too deeply	true lice: crab lice
decapod having eyes on short stalks and a broad flattened carapace with a small abdomen folded under the thorax and pincers
a louse that infests the pubic region of the human body
the edible flesh of any of various crabs
a quarrelsome grouch

crab (verb)	genus Phthirius (verb)
complain
fish for crab
scurry sideways like a crab
direct (an aircraft) into a crosswind