-stome Also -stomous.
[Greek stoma, mouth.]
This ending appears in some specialist words in zoology for animals with certain kinds of mouths, as in cyclostome, an eel-like jawless vertebrate with a circular sucking mouth, such as a lamprey or hagfish; protostome (Greek proto-, primitive), a multicellular organism whose mouth develops from a primary embryonic opening, such as a mollusc or arthropod; the peristome (Greek peri-, around) is the part surrounding the mouth of various invertebrates. Such nouns have associated adjectives in -stomous, such as physostomous (Greek physa, bladder), having the mouth and air bladder connected by an air duct. See also -tome.