Source : Webster's Revised Unabridged Dictionary (1913)

Smear \Smear\ (sm[=e]r), v. t. [imp. & p. p. {Smeared}
   (sm[=e]rd); p. pr. & vb. n. {Smearing}.] [OE. smeren,
   smerien, AS. smierwan, smyrwan, fr. smeoru fat, grease; akin
   to D. smeren, OHG. smirwen, G. schmieren, Icel. smyrja to
   anoint. See {Smear}, n.]
   1. To overspread with anything unctuous, viscous, or
      adhesive; to daub; as, to smear anything with oil. ``Smear
      the sleepy grooms with blood.'' --Shak.

   2. To soil in any way; to contaminate; to pollute; to stain
      morally; as, to be smeared with infamy. --Shak.

Smear \Smear\, n. [OE. smere,. smeoru fat, grease; akin to D.
   smeer, G. schmeer, OHG. smero, Icel. smj["o]r, Sw. & Dan.
   sm["o]r butter, Goth. sma['i]r[thorn]r fatness, smarna dung;
   cf. Lith. smarsas fat. Cf. {Smirch}.]
   1. A fat, oily substance; oinment. --Johnson.

   2. Hence, a spot made by, or as by, an unctuous or adhesive
      substance; a blot or blotch; a daub; a stain.

            Slow broke the morn, All damp and rolling vapor,
            with no sun, But in its place a moving smear of
            light.                                --Alexander
                                                  Smith.

Source : WordNet®

smear
     n 1: slanderous defamation [syn: {vilification}, {malignment}]
     2: a thin tissue or blood sample spread on a glass slide and
        stained for cytologic examination and diagnosis under a
        microscope [syn: {cytologic smear}, {cytosmear}]
     3: a blemish made by dirt; "he had a smudge on his cheek" [syn:
         {smudge}, {spot}, {blot}, {daub}, {smirch}, {slur}]
     4: an act that brings discredit to the person who does it; "he
        made a huge blot on his copybook" [syn: {blot}, {smirch},
        {spot}, {stain}]

smear
     v 1: stain by smearing or daubing with a dirty substance
     2: make a smudge on; soil by smudging [syn: {blur}, {smudge}, {smutch}]
     3: cover (a surface) by smearing (a substance) over it; "smear
        the wall with paint"; "daub the ceiling with plaster"
        [syn: {daub}]
     4: charge falsely or with malicious intent; attack the good
        name and reputation of someone; "The journalists have
        defamed me!" "The article in the paper sullied my
        reputation" [syn: {defame}, {slander}, {smirch}, {asperse},
         {denigrate}, {calumniate}, {sully}, {besmirch}]