thickening

US /ˈθɪk.ən.ɪŋ/
UK /ˈθɪk.ən.ɪŋ/
1.

dày lên

the process of becoming thicker or of making something become thicker:

:
This thickening of the airways causes them to narrow and makes it difficult to move air into and out of the lungs.
1.

dày lên

used for making something thicker:

:
Corn starch is used as a thickening agent.