verb
make or become hard or solid.
"the magma slowly solidifies and forms crystals"
Similar:
harden
go hard
set
freeze
ice over/up
gel
thicken
stiffen
congeal
clot
coagulate
curdle
cake
dry
bake
consolidate
ossify
fossilize
petrify
gelatinize
Opposite:
liquefy
melt
thaw
gasify
make stronger; reinforce.