1560s, "channeled, fluted," from the verb form of chamfer (q.v.). The meaning "cut or ground to a slope, beveled off" is attested from c. 1790.
Entries linking to chamfered
chamfer n.
c. 1600, "small groove cut in wood or stone," from French chanfraindre (15c., Modern French chanfreiner), past participle of chanfraint, a word of uncertain origin. The second element seems to be from Latin frangere "to break" (from PIE root *bhreg- "to break"); perhaps the whole word is cantum frangere "to break the edge."
The meaning "sloping surface in place of a square edge or corner" is attested from c. 1840, but the connection to the other sense is uncertain. As a verb from 1560s, "cut a furrow in;" from 1680s as "cut or grind into a symmetrical sloping edge." Related: Chamfering.