companion companion /kəmˈpænjən/

noun

1. () A friend who is frequently in the company of another  ( associate , familiar , yokefellow [ N. American] , companion , comrade , fellow )
   a friend who is frequently in the company of another
    Drinking companions
   drinking companions
    Comrades in arms
   comrades in arms
   
2. () A traveler who accompanies you  ( fellow traveler [American] , fellow traveller [Canadian, British] , companion )
   a traveler who accompanies you
     Emma's loyal dog was her constant companion.
   Emma's loyal dog was her constant companion.
   
3. One paid to accompany, assist or live with another  ( companion )
   one paid to accompany, assist or live with another
    He hired a companion to assist him during his recovery post-surgery.
   He hired a companion to assist him during his recovery post-surgery.
   
   

verb

1. Be a companion to somebody  ( companion , company , accompany , keep company )
   be a companion to somebody
     The loyal dog kept the lonely old man company.
   The loyal dog kept the lonely old man company.