raider

Etymology

raid + -er

noun

1. One who engages in a raid; a plunderer.
2. (business) A person who takes or attempts to take control of a firm against the will of current management by purchasing a controlling interest of stock and acquiring proxies.
3. (military) A special forces operative; a commando.
4. (military, naval) A warship which is light, maneuverable, and fast-moving.
5. A warplane on an air raid.
   It was attacked by an evening raider while pulling a passenger train in a south-east coast area. 1943 March and April, “Notes and News: Southern Locomotive Destroys Raider”, in Railway Magazine, page 119
6. A law enforcement official who conducts a raid on a building in search for illicit goods.
7. (informal) A person who uncovers evidence of improper behavior within governmental or private organizations.