[tres.tle] also tres.sel n [ME trestel, fr. MF, fr. (assumed) VL transtellum, fr. L transtillum, dim. of transtrum traverse beam, fr. trans across--more at through] (14c) 1: horse 2b
2: a braced frame serving as a support
3: a braced framework of timbers, piles, or steelwork for carrying a road or railroad over a depression