Callus n. : Same as Callosity

Callus 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.

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

Example:
How do I get a Callus on my fingertips quickly so I can be able to play guitar?

Taxonomy
callus, corns, skin, callus formation, rubbing, toes, Corns and calluses, soft corn, friction, irritation, pressure point, soft corns, free encyclopedia, the palms, infection, painful calluses, thickening, cause blisters.

Defination from the web:
callus · seborrheic keratosis · acrochordon · molluscum contagiosum · actinic keratosis · squamous cell carcinoma · basal cell carcinoma ... keratosis/hyperkeratosis (Seborrheic keratosis, Callus) · other epidermal thickening (Ichthyosis acquisita, Palmoplantar keratoderma) ...