Definition of callus in English:

Share this entry


Pronunciation: /ˈkaləs/
(also callous)


1A thickened and hardened part of the skin or soft tissue, especially in an area that has been subjected to friction.
Example sentences
  • In these areas, the skin often thickens into a callus, which when excessive can lead to an ulcer.
  • According to them, the genome of the ostrich has the ability to let the skin form calluses when the skin is abraded.
  • Then his fingers are under my chin and I can feel the tough spots of a couple calluses rub against my skin as he tilts my face up.
1.1 Medicine The bony healing tissue which forms around the ends of broken bone.
Example sentences
  • In the course of time, the callus is smoothed off and eventually the bone returns to its normal thickness.
  • Two cases were consistent with fracture callus based on the history of fall and injury to the spine and based on review of the concurrent cell block, which helped in making a definitive diagnosis.
  • It normally takes one to two weeks for a callus to form, then about six weeks for the bone fragments to unite.
1.2 Botany A hard formation of tissue, especially new tissue formed over a wound: [mass noun]: the exposed surface will quickly form healing callus
More example sentences
  • When a patch of bark is removed from a tree the wound is healed by the formation of a callus which differentiates into periderm.
  • The present paper describes the formation of surface callus on stem wounds of lime trees as observed by light and electron microscopy.
  • Furthermore, it was also observed that the callus formed from the radicle grew faster than the callus of plumule origin, thus reducing the formation of embryogenic callus.


Mid 16th century: from Latin callus (more commonly callum) 'hardened skin'.

  • callous from Late Middle English:

    The Latin source callosus means ‘hard-skinned’, and the word was originally used in this sense. The transference to ‘insensitive to others’ feelings', which happened in the late 17th century, has a parallel in thick-skinned. Callus (mid 16th century), for hardened skin, is from the same word.

Words that rhyme with callus

Callas, callous, Dallas, Pallas

For editors and proofreaders

Line breaks: cal¦lus

Share this entry

What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.