Pronunciation note Bulk and bulge most often are pronounced with the vowel /ʌ/Show Spelled[uh]Show IPA of buck. In South Midland and Southern U.S. the /ʊ/[oo] of book and bull commonly occurs among all speakers. Standard British speech has only /ʌ/[uh]. Both types exist in British regional speech, and both were brought to the colonies, where each came to predominate in a different area and was carried west by migration.
mid-15c., from O.N. bulki "a heap, ship's cargo," thus "goods loaded loose," perhaps lit. "rolled-up load," from P.Gmc. *bul-, from PIE *bhl-, from base *bhel- (2) "to blow, swell" (see bole). Meaning extended by confusion with obsolete bouk "belly" (from O.E. buc, from P.Gmc.
*bukaz, from PIE root meaning "to swell"), which led to sense of "size," first attested mid-15c.