From Longman Dictionary of Contemporary Englishsnipersnip‧er /ˈsnaɪpə $ -ər/ noun [countable] PMWSHOOTsomeone who shoots at people from a hidden position
Examples from the Corpus
sniper• A sniper's bullet pierced his windshield and hit him in the eye.• A sniper with a high-powered rifle and a telescopic lens scans the area for snakes and alligators.• Weapons were found at three locations believed to be used by snipers.• Movie sniper Jude Law and Rachel Weisz are covered in mud but still have their sights set on desire.• The second sniper could be anywhere.• One of them killed the sniper and probably saved some of the command group.• Therefore you keep your profile low until the sniper runs out of bullets.• The sniper is believed to be shooting from a hillside just east of the freeway.• For the first time, snipers appeared, firing from the roofs and windows of the public housing projects.