'Doer' definitions:

Definition of 'doer'

From: WordNet
noun
A person who acts and gets things done; "he's a principal actor in this affair"; "when you want something done get a doer"; "he's a miracle worker" [syn: actor, doer, worker]

Definition of 'Doer'

From: GCIDE
  • Doer \Do"er\, n. [From Do, v. t. & i.]
  • 1. One who does; one who performs or executes; one who is wont and ready to act; an actor; an agent. [1913 Webster]
  • The doers of the law shall be justified. -- Rom. ii. 13. [1913 Webster]
  • 2. (Scots Law) An agent or attorney; a factor. --Burrill. [1913 Webster]

Synonyms of 'doer'

From: Moby Thesaurus