[...] strictly speaking, words are "inflected" (i.e. they vary their "form") according to their "accidence" (from the Latin "accidentia", "accidental properties").
- Lyons (2004), Pag. 18

The standard reference grammars of Greek and Latin, and the grammars of modern languages which are based on classical principles, are generally divided into three section, not two: namely, into inflexion (or "accidence"), derivation (or "word-formation"), and syntax.
- Lyons (2004), Pag. 15