callus

plural calluses · hypercorrect plural calli

1. countableuncountableA hardened area of the skin (especially on the foot or hand) caused by repeated friction, wear or use.

   Sylvanshine had once been on a first date with a Xerox rep who had complex and slightly repulsive patterns of callus on her fingers from playing the banjo semi-professionally

   2011, David Foster Wallace, The Pale King, page 17

2. countableuncountableThe material of repair in fractures of bone; a substance exuded at the site of fracture, which is at first soft or cartilaginous in consistency, but is ultimately converted into true bone and unites the fragments into a single piece.
3. countableuncountablebiologyThe new formation over the end of a cutting, before it puts out rootlets.
4. countableuncountablebiologyIn orchids, a fleshy outgrowth from the labellum.
5. countableuncountablebiologyIn grasses, a hardened extension from the base of a floret, which may or may not elongate and is often covered in hairs or bristles.
6. countableuncountablebiologyA shining area on the frons of many species of Tabanomorpha (horse flies and relatives).

present singular third person calluses · participle present callusing · participle past callused · past callused

1. intransitiveTo form such hardened tissue.