[f. TRUE a.]
† 1. trans. To prove true, verify. Obs. rare–1.
1647. Ward, Simp. Cobler (1843), 81. Easilier told than tryed or trued.
2. To make true, as a piece of mechanism or the like; to place, adjust, or shape accurately; to give the precise required form or position to; to make accurately or perfectly straight, level, round, smooth, sharp, etc., as required. Often with up.
1841. Civil Eng. & Arch. Jrnl., IV. 234/1. An apparatus for ‘truing up’ the wheels of carriages and engines on railways.
1875. Knight, Dict. Mech., Marble-finishing Machine, one for truing and molding the edges of marble slabs for mantels, tables, etc.
1881. Greener, Gun, 267. The common barrels are done at half the cost of the best … by grinding them without turning and trueing them in the lathe.
1888. Hasluck, Model Engin. Handybk. (1900), 84. The next thing is to true up the valve-face on the cylinder.
Hence Truing vbl. sb. (also attrib.).
1851–4. Tomlinson, Cycl. Arts (1867), II. 40/1. The trueing of the lenses … being completed, the polishing is next proceeded with.
1877. Knight, Dict. Mech., Truing-tool, a device for truing the face of a grindstone, or any other surface.
1897. A. C. Pemberton, et al., Complete Cyclist, iii. 82. [The jointless’ rim] takes even less trueing than a good wood rim.
