The Collaborative International Dictionary of English v.0.48:

Mop \Mop\, n. [See Mope.]
   A made-up face; a grimace. "What mops and mowes it makes!"
   --Beau. & Fl.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Mop \Mop\, v. i.
   To make a wry mouth. [Obs.] --Shak.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Mop \Mop\, n. [CF. W. mop, mopa, Ir. moipal, Gael. moibeal,
   moibean; or OF. mappe a napkin (see Map, Napkin).]
   1. An implement for washing floors, or the like, made of a
      piece of cloth, or a collection of thrums, or coarse yarn,
      fastened to a handle.
      [1913 Webster]

   2. A fair where servants are hired. [Prov. Eng.]
      [1913 Webster]

   3. The young of any animal; also, a young girl; a moppet.
      [Prov. Eng.] --Halliwell.
      [1913 Webster]

   Mop head.
      (a) The end of a mop, to which the thrums or rags are
          fastened.
      (b) A clamp for holding the thrums or rags of a mop.
          [U.S.]
          [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Mop \Mop\, v. t. [imp. & p. p. Mopped; p. pr. & vb. n.
   Mopping.]
   To rub or wipe with a mop, or as with a mop; as, to mop a
   floor; to mop one's face with a handkerchief.
   [1913 Webster]

WordNet (r) 3.0 (2006):

mop
    n 1: cleaning implement consisting of absorbent material
         fastened to a handle; for cleaning floors [syn: swab,
         swob, mop]
    v 1: to wash or wipe with or as if with a mop; "Mop the hallway
         now"; "He mopped her forehead with a towel" [syn: wipe
         up, mop up, mop]
    2: make a sad face and thrust out one's lower lip; "mop and
       mow"; "The girl pouted" [syn: pout, mop, mow]