Emily Dickinson Lexicon

TRES'TLE, n. [tres'l; Fr. trêteau, for tresteau; W. três, a trace, a chain, a stretch, labor; tresiaw, to labor, that is, to strain; trestyl, a strainer, a trestle. This root occurs in stress and distress.]

1. The frame of a table. [Qu. D. driestal, a three-legged stool.]
2. A movable form for supporting any thing.
3. In bridges, a frame consisting of two posts with a head or cross beam and braces, on which rest the string-pieces. [This is the use of the word in New England. It is vulgarly pronounced trussel or trussl.] Trestle-trees, in a ship, are two strong bars of timber, fixed horizontally on the opposite sides of the lower mast-heat to support the frame of the top and the top-mast. Mar. Dict.