Etymology: probably from Middle English *trimmen to prepare, put in order, from Old English trymian, trymman to strengthen, arrange, from trum strong, firm; probably akin to Old English trēo tree, wood — more at tree
Date: circa 1521
1. to embellish with or as if with ribbons, lace, or ornaments <trim the Christmas tree> <the coat was trimmed with fur> 2. a. to administer a beating to ; thrash b. defeat <trimmed me at chess> 3. a. to make trim and neat especially by cutting or clipping <trim the hedges> b. to free of excess or extraneous matter by or as if by cutting <trim a budget> <trim down the inventory> c. to remove by or as if by cutting <trimmed thousands from federal payrolls — Grit> 4. a. (1) to cause (as a ship) to assume a desirable position in the water by arrangement of ballast, cargo, or passengers (2) to adjust (as an airplane or submarine) for horizontal movement or for motion upward or downward b. to adjust (as cargo or a sail) to a desired position 5. to adjust (as one's opinions) for reasons of expediency — often used in the phrase trim one's sails intransitive verb 1. a. to maintain neutrality between opposing parties or to favor each equally b. to change one's views for reasons of expediency 2. to assume or cause a boat to assume a desired position in the water <a boat that trims badly> II. adjective (trimmer; trimmest) Date: circa 1521 1. obsolete excellent, fine 2. ready for service or use; also in good physical condition <keeps trim by jogging> 3. exhibiting neatness, good order, or compactness of line or structure <trim houses> • trimly adverb • trimness noun III. adverb Date: 1529 in a trim manner ; trimly — used chiefly in combination <the trim-cut forest vistas — W. M. Thackeray> IV. noun Date: circa 1593 1. suitable or excellent condition <tries to keep in trim> 2. a. one's clothing or appearance b. material used for ornament or trimming c. the woodwork in the finish of a building especially around openings d. the interior furnishings of an automobile 3. a. the position of a ship or boat especially with reference to the horizontal; also the difference between the draft of a ship forward and that aft b. the relation between the plane of a sail and the direction of the ship c. the buoyancy status of a submarine d. the attitude of a lighter-than-air craft relative to a fore-and-aft horizontal plane e. the attitude with respect to wind axes at which an airplane will continue in level flight with free controls 4. something that is trimmed off or cut out 5. a haircut that neatens a previous haircut
New Collegiate Dictionary. 2001.