Stomachion would I guess imply “mouth battle” but is a corruption or misspelling of ostomachion — Wikipedia:
The word Ostomachion has as its roots in the Greek Ὀστομάχιον, which means “bone-fight”, from ὀστέον (osteon), “bone” and μάχη (mache), “fight, battle, combat”. Note that the manuscripts refer to the word as “Stomachion”, an apparent corruption of the original Greek….
The word stomach does indeed come from stoma (mouth). Bone-fight somewhat suggest bone wars, which I recently came across.
.i`` * ^ / . . . . . ` `~ 