labial palpus vs appendage

labial palpus and appendage both are nouns.

Word	Noun	Adjective	Verb	Adverb
labial palpus	Yes	No	No	No
appendage	Yes	No	No	No

As nouns, appendage is a hypernym of labial palpus; that is, appendage is a word with a broader meaning than labial palpus:

labial palpus: A labial palpus is either of the jointed appendages on the front of the mentum of an insect.
appendage: a natural prolongation or projection from a part of an organism either animal or plant

Other hypernyms of labial palpus include mouthpart, outgrowth, process.

labial palpus (noun)	appendage (noun)
A labial palpus is either of the jointed appendages on the front of the mentum of an insect.	a part that is joined to something larger
	an external body part that projects from the body
	a natural prolongation or projection from a part of an organism either animal or plant