in-friend

The significant other of a close friend, or the friend of a significant other.
See friend boyfriend girlfriend in-law

Taylor: So why are you friends with Corey?
Sena: Oh, because he's with Linda and she's my best friend, so Corey's my in-friend.

in-friend by Taylor N. Sena February 26, 2008

In Friend

When you meet a person who is so amazingly awesome you want to be best friends with them. Almost like being in love with someone but without the love part

Omg that guy watches Firefly as well I am so in friend with him!

In Friend by mrscobb22 July 13, 2011

fill-in friend 

A person who is a friend, only when your other friends are not present.

Also referred to as a "number two". Any social networking site has a Top Friends, and the number is your next best friend.

"Well, John isn't here, so I guess I'll have to talk to my fill-in friend."

"Amy had to go to the concert, so I guess it's just me and the number two."

fill-in friend by NOT a fill-in friend. May 3, 2009

Best friend in the world

The person who you trust your life with and you will never stop loveing because their amazing they also sometimes steal your food

Hey you see Ryan well that’s the best friend in the world to Ethan

Best friend in the world by Sword flash March 17, 2018

Best Friend-In Law

When you become best-friends with someone through marriage.

My best friend married Maya's best friend, so now we are best friend-in law's

Best Friend-In Law by Dangeriam December 9, 2009

friend-in-law 

The best friend of your wife or girlfriend, similar to a sister-in-law.

Are your coming with us to the game?
No, I have to go over to my friend-in-law's house to put up storm windows.

friend-in-law by Stephen Schaffter June 24, 2005

friend-in-law 

A good friend of a good friend. Even if you tend to hang out in the same circles often, this person would only qualify as more of an acquaintance.

Not someone you would desire to hang out with alone. Either because you only talk to the person large group settings and never really directly bonded, or because it's someone with whom you share nothing in common (other than a similar friend) and it would be awkward and uncomfortable to spend time alone together.

Most often it is a significant other's best friend.

"Nah, I don't see Megan anymore ever since Dave moved away. She was only a friend-in-law anyway."

friend-in-law by Jeff Jism November 27, 2007