A tress is an old-fashioned word for a curl or braid, but it’s used more loosely now as a word for long hair. If someone admires your beautiful tresses, they love your long flowing hair. Congratulations, Rapunzel.
Use the noun tress for a curl or ringlet, or as part of a head full of carefully curled tresses. Tresses has changed in meaning over the years and now refers to any hairstyle, but especially a woman’s long unbound hair. This word derives from the Old French tresse, which may stem from the Vulgar Latin trichia, "braid or rope," and the Greek root trikhia, "rope."