in the main in WordNet English dictionary

1. for the most part
   "he is mainly interested in butterflies"
   chiefly  principally  primarily  mainly  in the main  chiefly  principally  primarily  mainly  in the main 
   
2. without distinction of one from others
   "he is interested in snakes in general"
   generally  in general  in the main  generally  in general  in the main