tress (n.)
c.1300, "long lock of hair," from Old French tresse "a plait or braid of hair" (12c.), of uncertain origin, perhaps from Vulgar Latin *trichia "braid, rope," from Greek trikhia "rope," from thrix (genitive trikhos) "hair." Related: Tresses.
tress (v.)
"arrange in tresses," mid-14c., from Old French trecier (12c.), from tresse (see tress (n.)).