The word 'tress' has a direct lineage tracing back to the ancient Greek word for a single hair, 'thríx'. Through Vulgar Latin, this evolved into a term for a braid, which was adopted into Old French. Entering Middle English, it shed its exclusive association with braiding to denote any long, lock of hair, particularly of a woman. Thus, a term rooted in the basic concept of a hair strand now poetically describes an arranged or flowing lock.

The word is a simplex. It entered English from Old French 'tresse', meaning a braid or plait of hair. The Old French term likely derives from Vulgar Latin 'trichia', itself from Greek 'tríkha', meaning "hair" (from 'thríx', genitive 'trichós', meaning "hair").