Definition of lighten up
: to take things less seriously
First Known Use of lighten up
Rhymes with lighten up
belly-up, belly up, bottom-up, buckle up, bundle up, buttercup, butter up, buttoned-up, cover-up, cozy up, double up, dummy up, fancy up, follow-up, gussy up, higher-up, live it up, loosen up, loving cup, measure up, mix it up, open up, pick-me-up, pony up, power up, runner-up, seven-up, shoot-'em-up, stirrup cup, suck it up, suction cup, summing-up, up-and-up, wickiup, winding-up
Learn More about lighten up
Seen and Heard
What made you want to look up lighten up? Please tell us where you read or heard it (including the quote, if possible).