The journey of 'trestle' begins with the Latin 'transtrum', a nautical term for a crossbeam, particularly the thwart of a galley. This term passed into Vulgar Latin as 'transtellum', a diminutive form implying a smaller beam or support. It was then adopted into Old French as 'trestel', referring to a beam or bar used as a support. Entering Middle English, the word retained its core meaning of a supporting beam, which logically extended to describe the entire A-frame structure built from such beams. Thus, the modern meaning evolved from a single crossbar to the complete, stable framework used for supporting tables, bridges, and railroad tracks.

The word 'trestle' is a simplex form derived from the Old French 'trestel', which itself came from the Vulgar Latin 'transtellum', a diminutive of the Latin 'transtrum', meaning "beam, crossbar".