Word Origin & History
smearO.E. smerian "to anoint or rub with grease, oil, etc.," from P.Gmc. *smerthan (cf. O.N. smyrva, Dan. smøre, Swed. smörja, Du. smeren, O.H.G. smirwen, Ger. schmieren "to smear"), from PIE *smeru- "grease" (cf. Gk. myron "unguent, balsam," O.Ir. smi(u)r "marrow," O.E. smeoru "fat, grease").
Sense of "assault a public reputation with unsubstantiated charges" is from 1879. Noun meaning "mark or stain left by smearing" is first recorded 1611; sense of "small quantity prepared for microscopic examination" is from 1903.