verb (used with or without object), up·swelled, up·swelled or up·swol·len, up·swell·ing.

to swell up.

Origin of upswell

Middle English word dating back to 1350–1400; see origin at up-, swell Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for upswell


verb -swells, -swelling, -swelled, -swelled or -swollen

rare to swell up or cause to swell up
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012