accidence (n.) Look up accidence at
late 14c., in philosophy, "non-essential or incidental characteristic," also "part of grammar dealing with inflection" (mid-15c.), in some cases a misspelling of accidents, or else directly from Latin accidentia (used as a term in grammar by Quintilian), neuter plural of accidens, present participle of accidere "to happen, fall out; fall upon" (see accident). The grammar sense is because they are qualities which change in accordance with use but are not essential to the primary signification.