dam something up
phrasal verb with dam verb [ T ] uk/dæm/ us/dæm/ -mm-
在（河上）筑坝蓄水
to build a dam across a river in order to store water
不健康地压抑，郁积（情绪，尤其是愤怒，悲伤等）
If you dam up your feelings, especially anger or sadness, you do not allow yourself to express or show your feelings in a healthy way.