Types of friendships

The following is a list of terms that are used throughout the world to describe some types of friendships.

Acquaintance: a friend, but sharing of emotional ties isn't present. An example would be a coworker with whom you enjoy eating lunch or having coffee, but would not look to for emotional support.

Best friend (or close friend): a person(s) with whom someone shares extremely strong interpersonal ties with as a friend.

BFF ("Best Friend Forever"): slang originally coined on the internet and used primarily in the USA by women to describe a girl friend or close best friend. The slang BFF has been around longer than the internet.

Blood brother or blood sister: may refer to people related by birth, or a circle of friends who swear loyalty by mingling the blood of each member together.

Boston marriage: an American term used in the nineteenth and twentieth centuries to denote two women that lived together in the same household independent of male support. Relationships were not necessarily sexual. It was used to quell fears of lesbians after World War I.

Bro: In the USA, common term for best friends among men, oftentimes in college or early adulthood.

Buddy: In the USA, males often refer to each other as "buddies", for example, introducing a male friend as their "buddy", or a circle of male friends as "buddies".

Casual relationship or "Friends with benefits": the sexual or near-sexual and emotional relationship between two people who don't expect or demand to share a formal romantic relationship.

Comrade: means "ally", "friend", or "colleague" in a military or (usually) left-wing political connotation. This is the feeling of affinity that draws people together in time of war or when people have a mutual enemy or even a common goal. Friendship can be mistaken for comradeship. Former New York Times war correspondent Chris Hedges wrote:

We feel in wartime comradeship. We confuse this with friendship, with love. There are those, who will insist that the comradeship of war is love – the exotic glow that makes us in war feel as one people, one entity, is real, but this is part of war's intoxication. [...] Friends are predetermined; friendship takes place between men and women who possess an intellectual and emotional affinity for each other. But comradeship – that ecstatic bliss that comes with belonging to the crowd in wartime – is within our reach. We can all have comrades.[10]

As a war ends, or a common enemy recedes, many comrades return to being strangers, who lack friendship and have little in common.

Cross-sex friendship is one that is defined by a person having a friend of the opposite sex: a male who has a female friend, or a female who has a male friend. Historically cross-sex friendships have been rare. This is caused by the fact that often men would labor in order to support themselves and their family, while women stayed at home and took care of the housework and children. The lack of contact led to men forming friendships exclusively with their colleagues, and women forming friendships with other stay at home mothers. However, as women attended schools more and as their presence in the workplace increased, the segregated friendship dynamic was altered, and cross-sex friendships began to increase.

Frenemy: a portmanteau of the words fr(iend) and enemy, the term frenemy refers to someone who pretends to be a friend but actually is an enemy---a proverbial wolf in sheep’s clothing in the world of friendships. Most people have encountered a frenemy at one time of another, either at school, at work, or lurking in their neighborhood. The term frenemy was reportedly coined by a sister of author and journalist Jessica Mitford in 1977, and popularized more than twenty years later on the third season of Sex and the City. While most research on friendship and health has focused on the positive relationship between the two, a frenemy is a potential source of irritation and stress. One study by psychologist Dr. Julianne Holt-Lunstad found that unpredictable love-hate relationships characterized by ambivalence can lead to elevations in blood pressure. In a previous study, the same researcher found that blood pressure is higher around friends for whom they have mixed feelings than it is when they’re around people whom they clearly dislike.[11]

Fruit flies,[12] fag hag (female),[13] or fag stag (male):[14] denotes a person (usually heterosexual) who forms deep ties or close friendships with gay men. Men (gay or straight) who have lesbian friends have been referred to lezbros or lesbros.[15] The term has often been claimed by these straight members in gay-straight friendships, however some feel that it is derogatory.[16][17]

Imaginary friend: a non-physical friend created by a child. It may be seen as bad behavior or even taboo (some religious parents even consider their child to be possessed by an evil spirit), but is most commonly regarded as harmless, typical childhood behavior. The friend may or may not be human, and commonly serves a protective purpose.

Internet friendship: a form of friendship or romance which takes place over the Internet.

Mate: In the UK, Ireland, Australia, and New Zealand, blokes often refer to each other as 'mates', for example, introducing a male friend as their "mate", or a circle of male friends as "mates". In the UK, as well as Australia, this term has begun to be taken up by women as well as men.

Open relationship: a relationship, usually between two people, that agree each partner is free to have sexual intercourse with others outside the relationship. When this agreement is made between a married couple, it's called an "open marriage".

Pen pal: people who have a relationship via postal correspondence. They may or may not have met each other in person and may share either love, friendship, or simply an acquaintance between each other.

Roommate: a person who shares a room or apartment (flat) with another person and do not share a familial or romantic relationship.

Soulmate: the name given to someone who is considered the ultimate, true, and eternal half of the other's soul, in which the two are now and forever meant to be together.

Spiritual friendship: the Buddhist ideal of kalyana-mitra, that is a relationship between friends with a common interest, though one person may have more knowledge and experience than the other. The relationship is the responsibility of both friends and both bring something to it.