is a specific kind of: rima.

is a broader term that covers: cakehole, gob, hole, maw, trap, yap.

has as a part: dentition, teeth | clapper, glossa, lingua, tongue | buccal cavity | gingiva, gum | palate, roof of the mouth | salivary gland.

is a part of: mouth.

derivation: mouth, speak, talk, utter, verbalise, verbalize | mouth | mouth.