Why is the ninth month called September?
Old English belg, bylg (West Saxon), bælg (Anglian) "leather bag, purse, bellows," from Proto-Germanic *balgiz "bag" (cf. Old Norse belgr "bag, bellows," bylgja "billow," Gothic balgs "wineskin"), from PIE *bholgh-, from root *bhelgh- "to swell," an extension of *bhel- (2) "to blow, swell" (see bole). Meaning shifted to "body" (late 13c.), then focused to "abdomen" (mid-14c.). Meaning "bulging part or concave surface of anything" is 1590s. The West Germanic root had a figurative or extended sense of "anger, arrogance" (cf. Old English bolgenmod "enraged;" belgan (v.) "to become angry").
Indo-European languages commonly use the same word for both the external belly and the internal (stomach, womb, etc.), but the distinction of external and internal is somewhat present in English belly/stomach; Greek gastr- (see gastric) in classical language denoted the paunch or belly, while modern science uses it only in reference to the stomach as an organ. Fastidious avoidance of belly in speech and writing (compensated for by stretching the senses of imported stomach and abdomen, baby-talk tummy and misappropriated midriff) began late 18c. and the word was banished from Bibles in many early 19c. editions. Belly punch (n.) is attested from 1811.
"to swell out," 1620s, from belly (n.). Related: Bellied; bellying. Old English belgan meant "to be or become angry" (a figurative sense). A comparable Greek verb-from-noun, gastrizein, meant "to hit (someone) in the belly."
belly bel·ly (běl'ē)
The womb; the uterus.
The bulging, central part of a muscle. Also called venter.
Dead or ruined;
the seat of the carnal affections (Titus 1:12; Phil. 3:19; Rom. 16:18). The word is used symbolically for the heart (Prov. 18:8; 20:27; 22:18, marg.). The "belly of hell" signifies the grave or underworld (Jonah 2:2).
a thin plate of wood or a stretched membrane lying directly under the strings of a stringed musical instrument. It vibrates in response to the vibrations of the strings (transmitted to it by the bridge, an elastic piece of wood held under pressure or tension between the strings and soundboard), amplifying the faint sound produced by the string alone.