Etymology: Middle English smothe, from Old English smōth; akin to Old Saxon smōthi smooth
Date: before 12th century
(1) having a continuous even surface
(2) of a curve being the representation of a function with a continuous first derivative
(3) having or being a short even coat of hair <a smooth collie> — compare rough, wirehaired b. being without hair c. glabrous <a smooth leaf> d. causing no resistance to sliding 2. free from difficulties or impediments <the smooth course of his life> 3. even and uninterrupted in flow or flight 4. excessively and often artfully suave ; ingratiating <a smooth operator> 5. a. serene, equable <a smooth disposition> b. amiable, courteous 6. a. not sharp or harsh <a smooth sherry> b. free from lumps Synonyms: see level, easy, suave • smooth adverb • smoothly adverb • smoothness noun II. verb (smoothed; smoothing; smooths; also smoothes) Date: 15th century transitive verb 1. to make smooth 2. a. to free from what is harsh or disagreeable ; polish <smoothed out his style> b. soothe 3. to minimize (as a fault) especially in order to allay anger or ill will <his main job is to smooth over the friction that so often arises — Brian Crozier> 4. to free from obstruction or difficulty <conciliation smoothed the way to an agreement> 5. a. to press flat <smoothed down the folds of her dress> b. to remove expression from (one's face) ; compose 6. to cause to lie evenly and in order ; preen <a bird smoothing its feathers> 7. to free (as a graph or data) from irregularities intransitive verb to become smooth • smoother noun III. noun Date: 15th century 1. a smooth part 2. the act of smoothing 3. a smoothing implement
New Collegiate Dictionary. 2001.