Callus
Pronunciation : Cal"lus
Part of Speech : n.
Etymology : [L. See Callous.]
Definition : 1. (Med.) (a) Same as Callosity. (b
Defn: 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.
2. (Hort.)
Defn: The new formation over the end of a cutting, before it puts out rootlets.
Source : Webster's Unabridged Dictionary, 1913