mouthpart vs maxilliped

mouthpart and maxilliped both are nouns.

Word	Noun	Adjective	Verb	Adverb
mouthpart	Yes	No	No	No
maxilliped	Yes	No	No	No

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

mouthpart: any part of the mouth of an insect or other arthropod especially one adapted to a specific way of feeding
maxilliped: One of a set of three paired appendages on the thorax of a decapod crustacean, located just posterior to the maxillae and used in feeding.

Other hyponyms of mouthpart include gnathopod, maxillary palpus, labial palpus.

mouthpart (noun)	maxilliped (noun)
any part of the mouth of an insect or other arthropod especially one adapted to a specific way of feeding	One of a set of three paired appendages on the thorax of a decapod crustacean, located just posterior to the maxillae and used in feeding.