Is it ensure, insure, or assure?
1560s, "absolute ruler," from Old French despot (14c.), from Medieval Latin despota, from Greek despotes "master of a household, lord, absolute ruler," from PIE *dems-pota-; for first element see domestic (adj.); second element cognate with Latin potis, potens (see potent).
Faintly pejorative in Greek, progressively more so as used in various languages for Roman emperors, Christian rulers of Ottoman provinces, and Louis XVI during the French Revolution. The female equivalent was despoina "lady, queen, mistress," source of the proper name Despina.