Firm up, like Jell-O (3)
I believe the answer is:
set
(Other definitions for set that I've seen before include "plant" , "become firm" , "Prepared" , "conventional" , "Mount (precious stone)" .)
I believe the answer is:
set
(Other definitions for set that I've seen before include "plant" , "become firm" , "Prepared" , "conventional" , "Mount (precious stone)" .)