lighten up

Become or cause to become less serious or gloomy, and more cheerful. For example, Lighten up, Sam—it'll turn out all right. This slangy expression transfers reducing a physical weight to a change of mood or attitude.

Words Nearby lighten up

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.

How to use lighten up in a sentence

  • Now at length we were ready; and the countenances of the soldiers began to lighten up a little.

    Three Years in the Sixth Corps | George T. Stevens
  • The old gentleman did not lighten up any over the story, as Tom seemed to think he would.

  • It was clear and cloudless, the canopy above him, and he knew that ere long the moon would rise and lighten up his surroundings.

    '19,000' | Burford Delannoy
  • Difficulties which now seem insurmountable, will gradually disappear; subjects which now seem impenetrable, will soon lighten up.

    In the School-Room | John S. Hart
  • Perhaps a "make-up" man was inspired with a glimmer of editorial intelligence to "lighten up" the page.