Friend-once-removed

A friend of a friend; one that perhaps you've never met or you aren't well acquainted enough with to call them a proper friend, but your friend is close with.

The 'once' part can be changed depending upon how close this friend is; Your friend's friend's friend's friend would be your friend-thrice-removed.

I was talking with Jen the other day. Turns out my friend-once-removed Darren is in a band that's playing at the club on Friday. Wanna come see them with us?

Friends once removed

When you used to be friends with someone, then you stopped being friends, but eventually became friends again.

Three months after the break up, I decided I wanted to be friends once removed with Ted.