• A friend
  Friendship
  Friendship is a form of interpersonal relationship generally considered to be closer than association, although there is a range of degrees of intimacy in both friendships and associations. Friendship and association are often thought of as spanning across the same continuum...
  
   or acquaintance
  Interpersonal relationship
  An interpersonal relationship is an association between two or more people that may range from fleeting to enduring. This association may be based on limerence, love, solidarity, regular business interactions, or some other type of social commitment. Interpersonal relationships are formed in the...
  
   you associate yourself with
• Companion (caregiving)
  Companion (caregiving)
  In health care and caregiving, a companion, sitter, or private duty may be a nursing assistant or similar professional who is hired to work with one patient...
  
  , a nurse assistant or similar professional who assists a patient one-on-one
• Companion (ship), an architectural feature of ships
• Companion animal, a pet animal kept for companionship
• Companion parrot
  Companion parrot
  Companion parrot is a general term used for any parrot kept as a pet that interacts abundantly with its human counterpart. Generally, most species of parrot can make good companions....
  
  , a pet parrot that interacts with its owner
• Companion matrix, a matrix with a specific relation to its characteristic polynomial p
• Companion star, a star in a binary star system
• Companion weapon
  Companion weapon
  The term companion weapon is used in historical European martial arts to refer to an item used in conjunction with the larger weapon in the non-sword hand while fencing with a rapier or sword. The popular companion weapon forms include:*sword and buckler...
  
  , an object held in the non-sword hand while fencing
• Muhammad's companions, the Sahaba
• Companion cavalry
  Companion cavalry
  The Companions were the elite cavalry of the Macedonian army from the time of king Philip II of Macedon and reached the most prestige under Alexander the Great, and have been regarded as the best cavalry in the ancient world and the first shock cavalry...
  
  , Alexander the Great's elite cavalry
• Foot Companion, the primary type of soldier in Alexander the Great's army
• Lady's companion
  Lady's companion
  A lady's companion was a woman of genteel birth who acted as a paid companion for women of rank or wealth. The term was in use in the United Kingdom from at least the 18th century to the mid 20th century. It was related to the position of lady-in-waiting, which by the 19th century was only applied...
  
  , a genteel woman who acted as a companion for woman of rank or wealth
• Sober companion, an addiction treatment coach
• Companion planting
  Companion planting
  Companion planting is the planting of different crops in proximity , on the theory that they assist each other in nutrient uptake, pest control, pollination, and other factors necessary to increasing crop productivity...
  
  , planting of different crops in close physical proximity
• A handbook
  Handbook
  A handbook is a type of reference work, or other collection of instructions, that is intended to provide ready reference .A handbook is sometimes referred to as a vade mecum or pocket reference that is intended to be carried at all times.Handbooks may deal with any topic, and are generally...
  
   or guide book
  Guide book
  A guide book is a book for tourists or travelers that provides details about a geographic location, tourist destination, or itinerary. It is the written equivalent of a tour guide...
  
   or compendium
  Compendium
  A compendium is a concise, yet comprehensive compilation of a body of knowledge. A compendium may summarize a larger work. In most cases the body of knowledge will concern some delimited field of human interest or endeavour , while a "universal" encyclopedia can be referred to as a compendium of...
  
   e.g. Star Trek: Deep Space Nine Companion or The Oxford Companion to Music
• A member of a Holy Royal Arch
  Holy Royal Arch
  The Holy Royal Arch is a degree of Freemasonry. It is present in all main masonic systems, though in some it is part of 'mainstream' Freemasonry, and in others it is an 'additional' degree....
  
   chapter
• A domestic partner
• A concubine
• An intelligent conversational agent as in the Companions Project
• An companion in the Islamic religion: Sahabah
  Sahabah
  In Islam, the ' were the companions, disciples, scribes and family of the Islamic prophet...
  
  

Fiction

• Companion (Doctor Who)
  Companion (Doctor Who)
  In the long-running BBC television science fiction programme Doctor Who and related works, the term "companion" refers to a character who travels with, and shares the adventures of the Doctor. In most Doctor Who stories, the primary companion acts as both deuteragonist and audience surrogate...
  
  , a character who travels with the Doctor in the TV series Doctor Who
• Companion (Firefly), a type of courtesan and entertainer in the TV series Firefly
• The Companions or Heroes of the Lance, a group of heroes in the fictional Dragonlance world
• Companion (manga), an ongoing manga series published in Kodansha's Magazine Z

Music

• Companion (Patricia Barber album), a (1999) album by Patricia Barber
  Patricia Barber
  -Discography:* Split Premonition Records * Distortion of Love Antilles * Cafe Blue Blue Note, Premonition Records * Modern Cool Blue Note, Premonition Records...