Noun retainer has 3 senses
  1. retainer, consideration - a fee charged in advance to retain the services of someone
    --1 is a kind of fee
    --1 has particulars: quid pro quo, quid
  2. servant, retainer - a person working in the service of another (especially in the household)
    --2 is a kind of worker
    --2 has particulars:
     body servant; cabin boy; domestic, domestic help, house servant; factotum; familiar; lackey, flunky, flunkey; major-domo, seneschal; manservant; menial, dogsbody; scullion; servant girl, serving girl
  3. retainer - a dental appliance that holds teeth (or a prosthesis) in position after orthodontic treatment
    --3 is a kind of
    dental appliance