peristome vs body structure

peristome and body structure both are nouns.

Word	Noun	Adjective	Verb	Adverb
peristome	Yes	No	No	No
body structure	Yes	No	No	No

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

peristome: region around the mouth in various invertebrates
body structure: a particular complex anatomical part of a living thing and its construction and arrangement

Other hypernyms of peristome include anatomical structure, bodily structure, complex body part, structure.

peristome (noun)	body structure (noun)
region around the mouth in various invertebrates	a particular complex anatomical part of a living thing and its construction and arrangement
(botany) fringe of toothlike appendages surrounding the mouth of a moss capsule