bulge (n.)

c. 1200, "a wallet, leather bag," from Old French bouge, boulge "wallet, pouch, leather bag," or directly from Latin bulga "leather sack," from PIE *bhelgh- "to swell," extended form of root *bhel- (2) "to blow, swell." Sense of "a swelling, a rounded protuberance" is first recorded 1620s. Bilge (q.v.) might be a nautical variant. Meaning "bulging part of a military front" is from 1916.

bulge (v.)

"to protrude, swell out," 1670s, from bulge (n.). Related: Bulged; bulging.