Wiktionary
vb. (context idiomatic of a suggestion, idea, emotion, achievement, etc. English) To belittle or dismiss; to cast doubt upon; to debunk.
WordNet
v. be discouraging or negative about [syn: throw cold water on]
Usage examples of "pour cold water on".
Though Yestar will undoubtedly pour cold water on the idea, it will show us in a good light if Makri can at least feign some enthusiasm.
I thought him the one best qualified of all of us to pour cold water on my astonishing conjecture.
Sometimes these worked, but on other occasions Mma Ramotswe had been obliged to pour cold water on over-ambitious ideas.
Of course it was silly of her to encourage him in the first place, and she ought at least to have formed some idea of the passion she was arousing in time to pour cold water on it before it came to a head.
I kept trying to pour cold water on it, but I could see all the others visualizing that white head over their mantelpieces or what-not.