ambulacrum vs body part

ambulacrum and body part both are nouns.

Word	Noun	Adjective	Verb	Adverb
ambulacrum	Yes	No	No	No
body part	Yes	No	No	No

As nouns, body part is a hypernym of ambulacrum; that is, body part is a word with a broader meaning than ambulacrum:

ambulacrum: one of the five areas on the undersurface of an echinoderm on which the tube feet are located
body part: any part of an organism such as an organ or extremity

ambulacrum (noun)	body part (noun)
one of the five areas on the undersurface of an echinoderm on which the tube feet are located	any part of an organism such as an organ or extremity