v. [f. late L. exfoliāt- ppl. stem of exfoliāre to strip of leaves, f. ex- (see EX- pref.1) + folium leaf: see -ATE3. (In Fr. exfolier.) Cf. EFFOLIATE.]
1. trans. a. Pathol. To cast off, shed (the cuticle, the surface of a bone) in the form of ‘leaves’ or scales. b. Surg. To remove the surface of (a bone, etc.) by exfoliation.
1612. Woodall, Surg. Mate, Wks. (1653), 391. Nature doth of her self exfoliate, and cast off the part putrid.
1671. Shadwell, Humorists, V. 62. I have hurt my self just upon the Shin-bone, that was exfoliated.
1683. Salmon, Doron Med., II. 588. It is an excellent thing to scale and exfoliate Bones.
1799. Med. Jrnl., II. 446. The other [wound] continued … to exfoliate a little bone.
1810. Charac., in Ann. Reg. 1808, 116. Animals that exfoliate their cuticle annually.
2. intr. Of a bone, horny substance, a scar, the skin, etc.: To separate or come off in thin leaf-like layers or scales; to desquamate, scale off.
1676. Wiseman, Chirurg. Treat., II. vii. 184. The Heel-bone … rarely exfoliates by rough handling.
1774. Goldsm., Nat. Hist. (1862), II. I. vi. 26. [The horny helmet of the cassowary] exfoliates slowly like the beak.
1807. Med. Jrnl., XVII. 278. The eschar produced by the caustic exfoliated very kindly.
1818. Art Preserv. Feet, 177. The nails … are subject … to exfoliate.
1844–57. G. Bird, Urin. Deposits (ed. 5), 359. The warm bath was daily used as soon as the skin began to exfoliate.
1856. Kane, Arct. Expl., II. xi. 34. William Morton: down with a frozen heel; the bone exfoliating.
3. transf. a. Of the cellular tissue of trees: To peel off. Of the trunk: To throw off layers of bark. b. Of minerals, metals, rocks, etc.: To split into laminæ, come off in layers or scales.
1807. J. E. Smith, Phys. Bot., 23. The Cellular Integument exfoliates … in trees.
1811. Pinkerton, Petral., I. 591. Trunks of trees, lying one on the other … easily exfoliate, by drying in the open air.
1831. J. Holland, Manuf. Metals, I. 152. The wrought iron exfoliates, or separates in laminæ.
1839. Murchison, Silur. Syst., I. xxxvi. 501. The columnar greenstone exfoliates at the angles of the prisms.
1862. Dana, Man. Geol., 64. Before the blowpipe, [anhydrite] does not exfoliate like gypsum.
1879. Cassell’s Techn. Educ., IV. 145/1. The fire is only moderate at first, lest the cupel should crack and exfoliate by being too suddenly heated.
4. trans. In etymological sense: To unfold the leaves of; to open out, develop. In quot. fig.
1808. Knox & Jebb, Corr., I. 447. To make a sermon out of one of his discourses … partly, by exfoliating ideas, that are like rosebuds.
1877. Wraxall, trans. V. Hugo’s Misérables, V. xxxix. 26. Questions exfoliated themselves.
Hence Exfoliated, Exfoliating ppl. adjs.
1676. Wiseman, Chirurg. Treat., V. ix. 398. The exfoliated edges of the bone.
1859. Reeve, Brittany, 236. The columns were getting rusty and exfoliated.
1882. Times, 23 March, 9/5. The dust of the exfoliating skin.
