1an implement used for trimming off the unwanted or untidy parts of something:a hedge trimmer 2a person who adapts their views to the prevailing political trends for personal advancement. 3a person who decorates something:window trimmers 4 (also trimmer joist) Architecture a crosspiece fixed between full-length joists (and often across the end of truncated joists) to form part of the frame of an opening in a floor or roof. 5a person responsible for trimming the sails of a yacht. a person employed to arrange cargo or fuel in a ship’s hold. 6a small capacitor or other component used to tune a circuit such as a radio set.