The place where food goes after we swallow it derives its name from the Old English belig, meaning bag, which also evolved into bellows, a kind of silent accordion used to blow a fire higher. When belly was first applied to humans, it referred to the body in general, similar to how the German madensack, literally meaning worm sack, also refers to the human body. By the mid fourteenth century, however, belly had acquired its more specialized sense of stomach. Incidentally, the word stomach derives from the Greek word stoma, meaning mouth, which gave rise to stomakhos, meaning throat. In Greek, stomakhos came to be applied to the openings or “throats” into other internal organs, including that of the belly, and eventually its association with the belly made it a synonym for that organ. In English, stomach is first recorded in the fourteenth century; five hundred years later, in the late nineteenth century, it gave rise to a shortened form, tummy, originally used to ask children about their ailments.
The fatter central part of a muscle.