thicken
/ˈθɪkən/verb
- make or become thick or thicker（使）变厚（或粗、密、浓等）：
with obj. thicken the sauce with flour用面粉调浓沙司
no obj. the fog had thickened.雾变浓了。
短语
the plot thickens
- used when a situation is becoming more and more complicated and puzzling情节变得（更）复杂了, 情况变得（更）捉摸不定了。