outfall/ˈaʊtˌfɔl/EtymologyFrom Middle English outfallen, equivalent to out- + fall. Compare Dutch uitvallen (“to fall out, sally”), German ausfallen (“to fall out, lunge”), Swedish utfalla (“to fall out”).outfall means To burst forth, as upon an enemy; make a sally. Lexicurio rates it Rare gem — a strength score of 83 out of 100.verbTo burst forth, as upon an enemy; make a sally.nounA sudden eruption of troops from a fortified place; sally.A quarrel; a falling out.The point or place of discharge of a river, drain, culvert, sewer, etc.; mouth; embouchure.“West of Keswick a short descent at 1 in 122 brings the train down to the low-lying and marshy ground between Derwentwater and Bassenthwaite Lake and to the crossing of the Derwent - the outfall from Derwentwater, [...].”