yeah yeah /ˈjæ/

adverb

1. [Archaic] Not only so, but  ( yea [Archaic] , yeah [Archaic] )
   not only so, but
    I therein do rejoice, yea, and will rejoice
   I therein do rejoice, yea, and will rejoice
   

interjection

1. () [Informal] Affirmative answers or indications of agreement.  ( ay [Dialect] , aye [Dialect] , ya [Informal, South Africa] , certainly , sure [Informal] , yea [Informal] , yeah [Informal] , yes , uh-huh [Informal] , yah [Informal, UK] , yep [Informal] , yup [Informal] )
   Affirmative answers or indications of agreement.