glen (n.) Look up glen at Dictionary.com
"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.