"to soil with soot or mud, to sully," now usually figurative, 1590s, from be- + smirch.
Our Gayness and our Gilt are all besmyrcht. ["Henry V," IV.iii.110]
Related: Besmirched; besmirching.
Entries linking to besmirch
be-
word-forming element of verbs and nouns from verbs, with a wide range of meaning: "about, around; thoroughly, completely; to make, cause, seem; to provide with; at, on, to, for;" from Old English be- "about, around, on all sides" (the unstressed form of bi "by;" see by (prep.)). The form has remained by- in stressed positions and in some more modern formations (bylaw, bygones, bystander).
The Old English prefix also was used to make transitive verbs and as a privative prefix (as in behead). The sense "on all sides, all about" naturally grew to include intensive uses (as in bespatter "spatter about," therefore "spatter very much," besprinkle, etc.). Be- also can be causative, or have just about any sense required. The prefix was productive 16c.-17c. in forming useful words, many of which have not survived, such as bethwack "to thrash soundly" (1550s) and betongue "to assail in speech, to scold" (1630s).
smirch v.
late 15c., smorchen, "to discolor, to make dirty" (also compare bismorched, mid-15c.), a word of uncertain origin, perhaps (OED) from Old French esmorcher "to torture," which is perhaps also "befoul, stain," from es- "out" (see ex-) + morcher "to bite," from Latin morsus, past participle of mordēre "to bite" (see mordant). The sense perhaps was influenced by smear. The figurative meaning "dishonor, disgrace, discredit" is attested from 1820.