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.
Words nearby lose heart
losable,
loschmidt's number,
lose,
lose face,
lose ground,
lose heart,
lose it,
lose no time,
lose one's bearings,
lose one's buttons,
lose one's cool