early 14c., from Old French predicacion (12c.) and directly from Medieval Latin predicationem, from Latin praedicationem (nominative praedicatio) "a foretelling, prediction," noun of action from past participle stem of praedicare (see predicate (n.)).
mid-15c., a term in logic, from Middle French predicat and directly from Medieval Latin predicatum, from Latin praedicatum "that which is said of the subject," noun use of neuter past participle of praedicare "assert, proclaim, declare publicly," from prae- "forth, before" (see pre-) + dicare "proclaim," from stem of dicere "to speak, to say" (see diction). Grammatical sense is from 1630s. Related: Predicative; predicator; predicatory.
1887, from Latin praedicatus, past participle of praedicare "proclaim, announce" (see predicate (n.)).
1550s, back formation from predication, or else from Latin praedicatus, past participle of praedicare "proclaim, announce" (see predicate (n.)). Related: Predicated; predicating. Phrase predicated on "founded on, based on," is American English, first recorded 1766.