Definitions
1.nounA person using long-range small arms for precise attacks from a concealed position.
2.nounAny attacker using a non-contact weapon against a specific target from a concealed position.
3.nounOne who shoots from a concealed position.
4.nounOne who criticizes.
5.noun(ice hockey slang) A player who specializes in scoring goals."Alexander Ovechkin is often regarded as the greatest sniper of his generation."
6.nounA person or automated process set up by a person who or which attempts to win an online auction by placing a bid only seconds before the auction ends, leaving no time for other bidders to respond