cur ‧ dle /ˈkɜːdl $ ˈkɜːrdl/ BrE AmE verb [intransitive and transitive]
[ Date: 1500-1600 ; Origin: curd ]
1 . to become thicker or form curd, or to make a liquid do this:
Milk may curdle in warm weather.
2 . make your blood curdle to make you very frightened
⇨ ↑ bloodcurdling