Smooth Smooth, v. t. [imp. & p. p. Smoothed (sm[=oo]thd); p. pr. & vb. n. Smoothing.] [OE. smothen, smethen, AS. sm[=e][eth]ian; cf. LG. sm["o]den. See Smooth, a.] To make smooth; to make even on the surface by any means; as, to smooth a board with a plane; to smooth cloth with an iron. Specifically: (a) To free from obstruction; to make easy. Thou, Abelard! the last sad office pay, And smooth my passage to the realms of day. --Pope. (b) To free from harshness; to make flowing. In their motions harmony divine So smooths her charming tones that God's own ear Listens delighted. --Milton. (c) To palliate; to gloze; as, to smooth over a fault. (d) To give a smooth or calm appearance to. Each perturbation smoothed with outward calm. --Milton. (e) To ease; to regulate. --Dryden.