Second-friend 

A person who is friends with your friend and you don’t know them well enough to call them your own friend so they are your second-friend through association.

I bought my second-friend a small but appropriate birthday gift to be cordial.

Second-friend by candiedbones November 4, 2017

Second Friend

A second friend is a friend of your friend. They typically do not hang out with you unless you are hanging with your friend in common (known as a first friend). This is because hanging out with a second friend is usually awkward, as usually the only thing you have in common is that you both know your first friend. Sometimes if you spend enough time with a second friend, they can upgrade to a first friend. Then hanging out with that person is no longer awkward.

Say that Paul is your friend, and that David is his friend. But, sometimes you hang out with David because you hang out with Paul.

Michael: Hey man, you going to David's tonight?
Me: Is Paul going to be there?
Michael: Nah man, he's out of town.
Me: I probably won't go, he's more of a second friend.

Second Friend by Social Expert July 8, 2012

Second String Friend

Noun: a friend who is usually only called upon by a friend when a more primary/prominent friend is unavailable.

Taken from the term “second string” in an athletic competition situation. In football, if the star quarterback gets injured during a play, the second string is called off the bench to replace him/her. A “Second String Friend” is essentially benched until needed, if ever.

Synonyms: Plan B, Second Choice, Secondary Friend, Benched Until Needed

I got a call from X the other night. She had an extra ticket to a concert she bought for a friend, but they couldn’t make it so she called me to ask if I wanted to go because I am her Second String Friend.

Second String Friend by Deus-ex-machina August 26, 2020

Second Best Friend 

A best friend you can always relay on, if your actual best friend is not around, or not available for the time being. You often talk to them on facebook or text them a lot.

Anna, and Ray are second best friends, they always relay on each other when their other best friends are not around.

Second Best Friend by retzo June 10, 2011

Second degree friend

A friend of a friend.

Amy and I are second degree friends. I am friends with Tom who is friends with Amy.

Second degree friend by spornographer June 16, 2010

Second Pick Friend 

That one friend who you only hang out with when everyone else in the friend group is taken and you have no one else to partner up/hang out with. Usually tends to be someone who's half funny and a little bit interesting with a single quirk that allows them to be in your friend group.

Bob: Hey Joe, wanna partner for gym class?
Joe: Nah, I'm with Rick.
Bob: Alright how about you Deb?
Deb: I'm with Alan, sorry. Guess you'll have to partner with our Second Pick Friend, Zack
Bob: Ah shit.

Second Pick Friend by TheLastPizzaRoll February 14, 2020

Second Hand Friend Fist Bump 

The fist bump exchanged by two people with a mutual friend.

I don't know the kid but he's also friends with Alex, so we engaged in a Second Hand Friend Fist Bump.

Second Hand Friend Fist Bump by Mis-hap October 24, 2010