retainer Meaning, Definition & Usage

  1. noun a fee charged in advance to retain the services of someone
    consideration.
  2. noun a person working in the service of another (especially in the household)
    servant.
  3. noun a dental appliance that holds teeth (or a prosthesis) in position after orthodontic treatment

WordNet

Re*tain"er noun
Definitions
  1. One who, or that which, retains.
  2. One who is retained or kept in service; an attendant; an adherent; a hanger-on.
  3. Hence, a servant, not a domestic, but occasionally attending and wearing his master's livery. Cowell.
  4. (Law) (a) The act of a client by which he engages a lawyer or counselor to manage his cause. (b) The act of withholding what one has in his hands by virtue of some right. (c) A fee paid to engage a lawyer or counselor to maintain a cause, or to prevent his being employed by the opposing party in the case; -- called also retaining fee. Bouvier. Blackstone.
  5. The act of keeping dependents, or the state of being in dependence. Bacon.

Webster 1913