Trestle \Tres"tle\, n. [OF. trestel, tresteay, F. tr['e]teau; probably from L. transtillum a little crossbeam, dim. of transtrum a crossbeam. Cf. Transom.]

[Written also tressel.]

1. A movable frame or support for anything, as scaffolding, consisting of three or four legs secured to a top piece, and forming a sort of stool or horse, used by carpenters, masons, and other workmen; also, a kind of framework of strong posts or piles, and crossbeams, for supporting a bridge, the track of a railway, or the like.

2. The frame of a table.

Trestle board, a board used by architects, draughtsmen, and the like, for drawing designs upon; -- so called because commonly supported by trestles.

Trestle bridge. See under Bridge, n.

Source: Webster's Revised Unabridged Dictionary (1913)