I .
1.
( of rivers, lakes, etc. ) to become completely dry :
During the drought the river dried up.
2.
if a supply of sth dries up , there is gradually less of it until there is none left :
As she got older, offers of modelling work began to dry up.
3.
to suddenly stop talking because you do not know what to say next
II .
dry up | ˌdry sth ↔ ˈup
( BrE ) to dry dishes with a towel after you have washed them :
I'll wash and you can dry up.