窥探

kui1 tan4

to pry into or spy on; to snoop; to peep; to poke one's nose into; to peer; to get a glimpse of

窥视

kui1 shi4

to peep at; to spy on; to peek

偷窥

tou1 kui1

to peep; to peek; to act as voyeur

管窥

guan3 kui1

to look at sth through a bamboo tube; to have a restricted view

窥豹

kui1 bao4

lit. to see one spot on a leopard; fig. a restricted view