Meaning

noun the undulating movement of the surface of the open sea

noun a rounded elevation (especially one on an ocean floor)

noun a crescendo followed by a decrescendo

originFrom Middle English swellen, from Old English swellan (“to swell”), from Proto-West Germanic *swellan, from Proto-Germanic *swellaną (“to swell”), of unknown origin. Cognate with Saterland Frisian swälle (“to swell”), West Frisian swolle (“to swell”), Dutch zwellen (“to swell”), Low German swellen (“to swell”), German schwellen (“to swell”), Swedish svälla (“to swell”), Icelandic svella. The…

Etymology from Wiktionary, CC BY-SA 3.0