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lose heart

Become discouraged, as in The rescuers worked hard for the first few hours, but then they lost heart. This term uses heart in the sense of “courage” or “spirit.” [Mid-1800s] Also see lose one's heart to.

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RELATED WORDS

brood, sulk, chafe, despond, grumble, regret, grump, lament, repine, grieve, yearn, pine, moon, idle, despair, sink, ache, languish, bleed, fret
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.