Mech. [Short for TRAMMEL sb.1]
1. An instrument for describing ellipses; TRAMMEL sb.1 4.
1884. in Knight, Dict. Mech., Suppl.
2. The condition of correct adjustment of one part to another (obtained by using the tram-staff); used in the phrases in tram, out of tram. Originally used in reference to the adjustment of millstones, thence extended to other mechanical adjustments.
1892. in Cent. Dict.; and in later Dicts.
3. attrib. and Comb., as tram-pot, the step in which the toe of a millstone spindle revolves; tram-staff, a straight-edge used by millwrights in adjusting the millstone spindle (Cent. Dict., 1891).
1884. Knight, Dict. Mech., Suppl., Trampot (Milling), the seat in which the foot of the spindle is stepped.