潑冷水

泼冷水
pōlěngshuǐ
  1. to pour cold water on
  2. (fig.) to dampen sb's enthusiasm

CEDICT

Entry Composition

1 潑 pō
  1. to splash
  2. to spill
  3. rough and coarse
  4. brutish
2 冷水 lěngshuǐ
  1. cold water
  2. unboiled water
  3. fig. not yet ready (of plans)