thill /θɪl/ noun2 •One of the two long pieces of wood, extending before a vehicle, between which a horse is hitched; a shaft. •The shallow stratum of underclay that lies under a seam of coal; the bottom of a coal-seam.One by one, Janki leading, they crept into the old gallery – a six-foot way with a scant four feet from thill to roof. — 1888 formsthills
