1) Acht minus sechs 2) All-female band 3) Cologne couple 4) Company in Germany 5) Cube root of acht 6) Drei minus eins 7) German company 8) German couple 9) German two 10) Japanese rock music group 11) Prussian pair 12) Second in a german series 13) Square root of vier 14) Teutonic two 15) Two, to a Teuton 
ZWEI is an abbreviation for Zwei Was Eine Initially