late 14c., from Old French exhortacion and directly from Latin exhortationem (nominative exhortatio) "an exhortation, encouragement," noun of action from past participle stem of exhortari "to exhort, encourage," from ex- "thoroughly" (see ex-) + hortari "encourage, urge" (see hortatory). From early 15c. as "speech for the purpose of exhortation."
