/ spuːk; NAmE / noun , verb
■ noun ( informal )
1.
a ghost :
a castle haunted by spooks
2.
( especially NAmE ) a spy :
a CIA spook
■ verb
( informal , especially NAmE ) to frighten a person or an animal; to become frightened :
[ vn ] [ usually passive ]
We were spooked by the strange noises and lights.
[ v ]
The horse spooked at the siren.
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WORD ORIGIN
early 19th cent.: from Dutch , of unknown origin.