companion in WordNet English dictionary

1. be a companion to somebody
   company  companion  accompany  keep company 
   

1. a friend who is frequently in the company of another
   "drinking companions"; "comrades in arms"
   companion  comrade  fellow  familiar  associate 
   
2. one paid to accompany or assist or live with another
   companion 
   
3. a traveler who accompanies you
   companion  fellow traveler  fellow traveller