callus

UK: /ˈkæləs/ US: /ˈkæləs/ ,(kal′əs)

Inflections of 'callus' (v): (⇒ conjugate)

calluses

v 3rd person singular

callusing

v pres p

callused

v past

callused

v past p

WordReference Random House Learner's Dictionary of American English © 2025

cal•lus /ˈkæləs/   n. [countable] , pl. -lus•es. 

1. Pathology, Physiology a hardened or thickened part of the skin, caused by rubbing.

WordReference Random House Unabridged Dictionary of American English © 2025

cal•lus  (kal′əs), n., pl. -lus•es, v., -lused, -lus•ing. 
n. 

1. 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.
2. Also, callose. [Bot.]
   • Botany the tissue that forms over the wounds of plants, protecting the inner tissues and causing healing.
   • Botany a deposit on the perforated area of a sieve tube.
   • Botany (in grasses) a tough swelling at the base of a lemma or palea.

v.i. 

3. to form a callus.

v.t. 

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

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

Collins Concise English Dictionary © HarperCollins Publishers::

callus / ˈkæləs/ noun (-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. a mass of hard protective tissue produced in woody plants at the site of an injury
4. a mass of undifferentiated cells produced as the first stage in tissue culture

Etymology: 16th Century: from Latin, variant of callum hardened skin