Source : Webster's Revised Unabridged Dictionary (1913)

Smoothing \Smooth"ing\, a. & n.
   fr. {Smooth}, v.

   {Smoothing iron}, an iron instrument with a polished face,
      for smoothing clothes; a sadiron; a flatiron.

   {Smoothing plane}, a short, finely set plane, for smoothing
      and finishing work.

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.