water down
[phrasal verb] 1 water (something) down or water down (something)
: to make (an alcoholic drink) weaker by adding water to it掺水冲淡(酒精饮料);稀释;给…加水 2
disapproving : to make (something) less effective, powerful, etc.削弱,减少(效果、影响等) — see also watered-down