An Etymological Dictionary of the German Language/Flasche
Flasche, f., ‘bottle, flask,’ from the equiv. MidHG. vlasche, OHG. flasca, f. (MidHG. also vlesche with mutation); comp. Du. flesch, AS. flasce, f., E. flask, OIc. (found early) flaska, f., Goth. *flaskô, whence Finn. lasku. The word is recorded in Teut. at an early period, but on account of its correspondence with the Rom. words for ‘bottle,’ it may have been borrowed; comp. MidLat. flasco (occurs very early), Ital. fiasco, ModFr. flacon. Some etymologists derive MidLat. flasco from Lat. vasculum. An exhaustive history of these cognates has not yet been attempted.