If you step on one after nightfall, it will be useless to objurgate.
a memory charm or spell in the Harry Potter books that makes one forget
1610s, from Latin obiurgatus, past participle of obiurgare "to chide, rebuke," from ob- (see ob-) + iurgare "to quarrel, scold," from phrase iure agere "to deal in a lawsuit," from ablative of ius "right; law; suit" (see just (adj.)) + agere "to do, act, set in motion" (see act (n.)). Related: Objurgatory.