My free interpretation:
Repetieren is a german verb = to repeat
Repetieren comes from Latin repetere: re-petere, re = again, petere = do/make => do again.
Repetier is generally used with other words, e.g. Repetier-Gewehr = repeater (repeating rifle/gun).
Pronunciation:
http://dict.leo.org/#/search=repetieren ... wSingle=on