ab·seil I. \ˈäpˌzīl, -īəl\noun (-s) Etymology: German abseil-, from abseilen to descend by a rope, from ab- down + seil rope : descent in mountaineering by means of a rope looped over a projection above — compare rappel II. \ˈäpˌzīl, -īəl\intransitive verb (-ed/-ing/-s-s) Etymology:abseil, noun chiefly Britain: rappel II • ab·seil·er\-ə(r)\noun