Lewis Short
callōsĭtas (noun F) : callosus
* Hardness of skin, callousness (post-class.), Scrib. Comp. 36: fistulae,Veg. 3, 27, 3.—Trop., hardness, a hardening: usus communis,Tert. Testim. Anim. 8: voluntarii erroris,id. adv. Nat. 2, 1.
Charlton T. Lewis, Charles Short, A Latin Dictionary