[f. THIN v.1 + -ING1.] The action of THIN v.1, in various senses; reduction or decrease in thickness, closeness, number, density, etc. Also with out, off, away, up, etc.
c. 1000. Sax. Leechd., II. 260. Læcedomas þa þe þynnunge mæʓen hæbben.
1398. Trevisa, Barth. De P. R., XIX. xi. (Bodl. MS.). White mater is igendred of thynnynge and spredinge of aier.
1799. J. Robertson, Agric. Perth, 257. Weeded down by various thinnings.
1839. Ure, Dict. Arts, 1269. The thinning up, or quantity of turpentine required to bring it to its proper consistence.
1851. Carpenter, Man. Phys. (ed. 2), 268. By the thinning-away of its wall at its most projecting part.
1868. Rep. U. S. Commissioner Agric. (1869), 423. Upon thinning out, enough plants were cast away to have run at least twelve rows additional.
b. concr. usually pl. That which is removed in the process of thinning. (Cf. sweepings.)
1771. Usef. Proj., in Ann. Reg., 115/2. Sir John … never receives less than a guinea an acre in thinnings throughout his plantations.
1805. R. W. Dickson, Pract. Agric., I. Pl. xxx. 110. A fir paling of the horizontal kind, made from the thinning of trees of that kind.
1893. Jrnl. R. Agric. Soc., Dec., 826. Thinnings and rubbish should be immediately removed and burnt.
