1An intransitive verb meaning to lose interest or for enjoyment/atmosphere to be dampened — to fall flat or be spoiled.
その冗談で場の雰囲気が一気に興ざめることがある。
That kind of joke can sometimes kill the atmosphere in an instant.
期待が大きすぎて、実際を見て興ざめてしまった。
My expectations were too high, and seeing reality I lost interest.
彼の無神経な発言にみんなが興ざめた。
Everyone was put off by his insensitive remark.