whumpf exclamation 1noun 1verb 1forms 3 exclamation1 •A dull, soft sound as of something hollow collapsing. noun1 •The collapsing of a weak part of the snowpack, accompanied by a whumpf noise and potentially leading to an avalanche. verb1 •Of snow: to collapse in this manner.Even by the end of the month observers in the Northern and Central Mountains were still reporting collapsing and "whumpfing" snow; conditions that typically disappear in February. — 1999 formswhumpfed · whumpfing · whumpfs