from
The Collaborative International Dictionary of English v.0.48
Rigor \Ri"gor\, n. [L. See {Rigor}., below.]
1. Rigidity; stiffness.
[1913 Webster]
2. (ed.) A sense of chilliness, with contraction of the skin;
a convulsive shuddering or tremor, as in the chill
preceding a fever.
[1913 Webster]
{Rigor caloris}[L., rigor of heat] (Physiol.), a form of
rigor mortis induced by heat, as when the muscle of a
mammal is heated to about 50[deg] C.
{Rigor mortis}[L., rigor of death], death stiffening; the
rigidity of the muscles that occurs at death and lasts
till decomposition sets in. It is due to the formation of
myosin by the coagulation of the contents of the
individual muscle fibers.
[1913 Webster]