Grog
The spirit, usually rum, served on board Naval ships. The name comes in a roundabout way from Admiral Edward Vernon (1864-1757). He was nicknamed Old Grog by his men from his habit of walking the quarter-deck in all weathers in a grogram cloak (a coat from a coarse fabric made of silk or wool, often stiffened with gum).
When he introduced to the navy the practice of serving rum mixed water, instead of neat rum, with a view to economy, his concoction was at once named by the personnel "grog".