Callus

v. be covered with callouses, be covered with patches of hardened skin

n. hardened area of skin; bunch of undifferentiated plant cells that are capable to regenerate a complete plant in some species (Biology)

A callus (or callous) is an especially toughened area of skin which has become relatively thick and hard as a response to repeated contact or pressure. In botany, the term is also used to announce a condition of thickened surfaces of leaves or other plant parts. Since repeated contact is required, calluses are most often found on hands or feet. Calluses are generally not harmful, but may sometimes lead to other problems, such as infection. Shoes that fit tightly can often produce calluses on the feet. String instrument players develop calluses where their fingers make contact with the strings, but these calluses are often desirable as they help alleviate the pain from the tension of the strings and make playing easier. Dancers often develop calluses on the soles of their feet from dancing barefoot, which makes performing turns less difficult. Video game players may develop calluses on their thumbs, especially if using a controller with a non-ergonomic D-pad design. Frequent use of a writing implement may lead to a callus on the middle finger, commonly known as a "writer's bump".
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Callus /cal·lus/ [L.] 1. localized hyperplasia of the stratum corneum of the epidermis due to pressure or friction. 2. [more]Callus - Community and Resources

Noun
1. an area of skin that is thick or hard from continual pressure or friction (as the sole of the foot)
(synonym) callosity
(hypernym) hardening
(hyponym) corn, clavus
2. bony tissue formed during the healing of a fractured bone
(hypernym) scar, cicatrix, cicatrice
(hyponym) chestnut
3. (botany) an isolated thickening of tissue, especially a stiff protuberance on the lip of an orchid
(hypernym) plant process, enation
(classification) botany, phytology
Verb
1. cause a callus to form on; "The long march had callused his feet"
(hypernym) harden, indurate
(derivation) callosity
2. form a callus or calluses; "His foot callused"
(hypernym) harden, indurate
(derivation) callosity

(n.)
The new formation over the end of a cutting, before it puts out rootlets.
  

(n.)
The material of repair in fractures of bone; a substance exuded at the site of fracture, which is at first soft or cartilaginous in consistence, but is ultimately converted into true bone and unites the fragments into a single piece.
  

(n.)
Same as Callosity