"sovereign, ruler, feudal lord or baron," 1807, suzereign, from French suzerain (14c., Old French suserain), noun use of an adjective meaning "sovereign but not supreme," from the adverb sus "up, above," on analogy of soverain (see sovereign (adj.)). Old French sus is from Vulgar Latin *susum, from Latin sursum "upward, above," a contraction of subversum, from subvertere "turn upside down, overturn, overthrow" (see subvert). The fem. form is suzeraine (1880).

late 15c., suserente, "supremacy," from Old French suserenete "office or jurisdiction of a suzerain" (Modern French suzeraineté), from suserain (see suzerain). The modern use, "position, rank, dignity, or power of a suzerain" (by 1823) probably is a re-borrowing and for the first 20 years or so it was treated as a French word in English.