callus

noun, plural cal·lus·es.

1. Pathology, Physiology.
   1. a hardened or thickened part of the skin; a callosity.
   2. a new growth of osseous matter at the ends of a fractured bone, serving to unite them.
2. Also callose. Botany.
   1. the tissue that forms over the wounds of plants, protecting the inner tissues and causing healing.
   2. a deposit on the perforated area of a sieve tube.
   3. (in grasses) a tough swelling at the base of a lemma or palea.

verb (used without object), cal·lused, cal·lus·ing.

3. to form a callus.

verb (used with object), cal·lused, cal·lus·ing.

4. to produce a callus or calluses on: Heavy work callused his hands.

noun plural -luses

1. Also called: callosity an area of skin that is hard or thick, esp on the palm of the hand or sole of the foot, as from continual friction or pressure
2. an area of bony tissue formed during the healing of a fractured bone
3. botany
   1. a mass of hard protective tissue produced in woody plants at the site of an injury
   2. an accumulation of callose in the sieve tubes
4. biotechnology a mass of undifferentiated cells produced as the first stage in tissue culture

verb

5. to produce or cause to produce a callus

n.

“hardened skin,” 1560s, from Latin callus, variant of callum “hard skin,” related to callere “be hard,” from PIE root *kal- “hard” (cf. Sanskrit kalika “bud,” Old Irish calath “hard,” Old Church Slavonic kaliti “to cool, harden”).

n. pl. cal•lus•es

1. callosity
2. The hard bony tissue that develops around the ends of a fractured bone during healing.

1. An area of the skin that has become hardened and thick, usually because of prolonged pressure or rubbing.
2. The hard bony tissue that develops around the ends of a fractured bone during healing.