"narrow valley," late 15c., from Scottish, from Gaelic gleann "mountain valley" (cognate with Old Irish glenn, Welsh glyn). Common in place names such as Glenlivet (1822), a kind of whiskey, named for the place it was first made (literally "the glen of the Livet," a tributary of the Avon); and Glengarry (1841) a kind of men's cap, of Highland origin, named for a valley in Inverness-shire.