[abbr. SE grogram, ‘a coarse fabric of silk, of mohair and wool, or of these mixed with silk’ (OED). Orig. applied as a nickname for Admiral Vernon, known as ‘Old Grog’, because he wore a grogram cloak. The name was transferred to the mixture of rum and water, which in August 1740 he ordered should be served instead of the RN’s usual issue of neat rum; however, the 19C Roxburghe Ballads collection includes one such ballad, dated 1672–85, which contains the word ‘grog’ and would thus seem to overturn this otherwise accepted ety. Further note M. Quinion (letter 14/03/08): ‘Ebsworth, [...] was a scrupulous editor, and his dating ought to be on the mark. But it’s a one-off example. I’m also bothered by finding the same line in a ballad about a sailor named Jack Robinson, which was published in a collection of comic songs by Thomas Hudson in 1818. The three lines read “Ibruisn a public-house then they both sot down / And talk’d of admirals of high renown / And drunk’d as much grog as come to half-a-crown.” The unknown author may just have borrowed a couple of good lines, of course (such plagiarism was common) but the reference to admirals, and the general tone of the piece, hints that it (and presumably therefore the supposed Roxburghe Ballad) might have been written after 1740 in knowledge of the Vernon story.’]
[late 17C+] (alsoMr Grog) alcohol, orig. rum but soon generic for any intoxicating liquor, whether beer or spirits.