Meaning

noun a British peer of the highest rank

noun a nobleman (in various countries) of high rank

originFrom Old French duc, through Middle English duk, duke, from Latin dux, ducis. Displaced native Old English heretoga. Was present as duc in late Old English, from the same Latin source. Doublet of doge, duc, duce, and dux. Ultimately from Proto-Indo-European *dewk-, which is also the source of the second component in German Herzog. The “fist” sense is thought to be Cockney rhyming slang where…

Etymology from Wiktionary, CC BY-SA 3.0