'Raider' definitions:

Definition of 'raider'

From: WordNet
noun
Someone who takes spoils or plunder (as in war) [syn: plunderer, pillager, looter, spoiler, despoiler, raider, freebooter]
noun
A corporate investor who intends to take over a company by buying a controlling interest in its stock and installing new management

Definition of 'Raider'

From: GCIDE
  • Raider \Raid"er\ (r[=a]d"[~e]r), n. One who engages in a raid. [U.S.] [1913 Webster]