Meaning of TRACE in English
n. each of the two side-straps, chains, or ropes by which a horse draws a vehicle. kick over the traces become insubordinate or reckless. trace-horse a horse that draws in traces or by a single trace, esp. one hitched on to help uphill etc.
[ ME f. OF trais, pl. of TRAIT ]
Concise Oxford English dictionary. Краткий оксфордский словарь английского языка. 2012