Also (erron.) callous. Pl. calluses. [a. L. callus hardened skin.]
1. Phys. and Pathol. A callous formation; a hardened and thickened part of the skin, or of some other tissue naturally soft; also applied to natural thickenings of the skin, etc.; = CALLOSITY 2.
1563. T. Gale, Antidot., II. 56. It doth dry fistulas which haue not callus indurated.
1656. Ridgley, Pract. Physic, 157. The Callous must be first removed.
1722. De Foe, Plague (1884), 249. Spots … as … hard as a piece of Callous or Horn.
1769. Pennant, Zool., III. 280. Between the eyes and the mouth is a hard callus.
1858. O. W. Holmes, Aut. Breakf.-t., 191. When I have established a pair of well-pronounced feathering-calluses on my thumbs.
1873. Tristram, Moab, xv. 292. Even in the young [ibex] kid there is a hard callous … on the front of the knee.
2. Pathol. ‘The bony material thrown out around and between the two ends of a fractured bone during the process of healing’ (Syd. Soc. Lex.).
1678. Jones, Heart & Right Sov., 396. Nature supplyes the … breaches, in our bones, by a callus, or hardness of the like kind.
1713. Cheselden, Anat., I. i. (1726), 8. The Callus from the broken ends of a bone that is not set.
1845. Todd & Bowman, Phys. Anat., I. 125. The permanent callus has all the characters of true bone.
1855. Holden, Hum. Osteol. (1878), 37. This ferule termed the provisional callus is not removed until the fracture has been thoroughly repaired.
3. Bot. A hard formation in or on plants.
1870. Hooker, Stud. Flora, 109. Rubus fruticosus … rooting from a callus at the tip.
1882. Vines, Sachs’ Bot., 173. The callus formed between the bark and the wood, when the stem is cut off above the root.
4. fig. A callous state of feeling, etc.
1692. Burnet, Past. Care, vii. 73. A Callus that he Contracts, by his insensible way of handling Divine Matters.
1858. O. W. Holmes, Aut. Breakf.-t., 341. They [editors] have nothing to do but to develope enormous calluses at every point of contact with authorship.
