on in WordNet English dictionary

1. with a forward motion
   "we drove along admiring the view"; "the horse trotted along at a steady pace"; "the circus traveled on to the next city"; "move along"; "march on"
   along  on  along  on 
   
2. indicates continuity or persistence or concentration
   "his spirit lives on"; "shall I read on?"
   on  on 
   
3. in a state required for something to function or be effective
   "turn the lights on"; "get a load on"
   on  on 
   

1. in operation or operational
   "left the oven on"; "the switch is in the on position"
   on 
   
2. (of events) planned or scheduled
   "the picnic is on, rain or shine"; "we have nothing on for Friday night"
   on