Rigor: A word with two different but related meanings in medicine: 1. A chill, usually with shivering, as at the onset of high fever and chills. 2. Rigidity, as in rigor mortis, the rigidity of a body after death. The alternate spelling rigour is chiefly British. From the French, from the Latin rigor, meaning stiffness, from rigere, to be stiff.
-ine is a suffix used in chemistry to denote two kinds of substance. The first is a chemically basic and alkaloidal substance.
A suffix is a word element placed at the end of a word that changes the meaning of the word. In the terms tonsill/itis, and tonsill/ectomy, the suffixes are -itis (inflammation) and -ectomy (excision, removal). Changing the suffix changes the meaning of the word.