self-deprecation (n.)

c. 1500, deprecacioun, "prayer to avert evil, earnest desire for exemption or deliverance," from Old French deprecation and directly from Latin deprecationem (nominative deprecatio) "a warding off or averting by prayer," noun of action from past-participle stem of deprecari "plead in excuse; avert by prayer," literally "to pray (something) away," from de "away" (see de-) + precari "to pray" (from PIE root *prek- "to ask, entreat"). Sense of "disapproval, earnest expression of feeling against" is by 1610s.