callus

[ kal-uh s ]

/ ˈkæl əs /

SEE MORE SYNONYMS FOR callus ON THESAURUS.COM

noun, plural cal·lus·es.

Pathology, Physiology.

a hardened or thickened part of the skin; a callosity.
a new growth of osseous matter at the ends of a fractured bone, serving to unite them.

Also callose. Botany.

the tissue that forms over the wounds of plants, protecting the inner tissues and causing healing.
a deposit on the perforated area of a sieve tube.
(in grasses) a tough swelling at the base of a lemma or palea.

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

to form a callus.

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

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

Nearby words

Origin of callus

1555–65; < Latin callus, masculine variant of callum; see callous

Related formsun·cal·lused, adjective

Can be confusedcallous callus

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for callus

Wounds upon plants begin to heal by the formation of loose cellular matter which gives rise to a mass of tissue known as a callus.
The Nursery Book|Liberty Hyde Bailey
Later, the nerve may become involved in callus, or be damaged by the pressure of ill-fitting splints.
Manual of Surgery Volume Second: Extremities--Head--Neck. Sixth Edition.|Alexander Miles
If the center of the wound falls in, the callus cannot cover it, and an open sore remains.
The Apple-Tree|L. H. Bailey
After the bones have united, it will take some weeks to consolidate the uniting material and render the “callus,” or union, firm.
A Treatise on Anatomy, Physiology, and Hygiene (Revised Edition)|Calvin Cutter

The callus formation indicates the favorable progress of repair, but with the fragments in faulty position.
Gunshot Roentgenograms|Clyde S. Ford

British Dictionary definitions for callus

callus

/ (ˈkæləs) /

noun plural -luses

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

an area of bony tissue formed during the healing of a fractured bone

botany

a mass of hard protective tissue produced in woody plants at the site of an injury
an accumulation of callose in the sieve tubes

biotechnology a mass of undifferentiated cells produced as the first stage in tissue culture

verb

to produce or cause to produce a callus

Word Origin for callus

C16: from Latin, variant of callum hardened skin

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for callus

callus

"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").

Medicine definitions for callus