callus

American  

[kal-uhs] / ˈkæl əs /

noun

plural

calluses

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. Botany. Also

   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.

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verb (used without object)

callused, callusing

1. to form a callus.

verb (used with object)

callused, callusing

1. to produce a callus or calluses on.

   Heavy work callused his hands.

callus British  

/ ˈkæləs /

noun

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

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verb

1. to produce or cause to produce a callus

callus Scientific  

/ kăl′əs /

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.

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Other Word Forms

• uncallused adjective

Etymology

Origin of callus

First recorded in 1555–65; from Latin callus, masculine variant of callum “tough skin, any hard substance”; callous

Example Sentences

“I want to build up a callus of hard work,” Fisch said.

From Seattle Times • Apr. 3, 2024

The cells formed a tumorlike tissue known as callus that could then be coaxed to grow into a seedling.

From Science Magazine • May 17, 2023

Or maybe you don’t notice it at all, until one day you found a little rough patch and realized it wasn’t any old callus, but a virus that had made a home beneath your skin.

From Slate • Oct. 6, 2022

Will I have to ask for more time spent on that callus?

From Los Angeles Times • Sep. 22, 2022

Carl picked at a callus on his thumb and Billy Buck watched a spider crawling up the wall.

From "The Red Pony" by John Steinbeck