When two people have had sex with the same person, but not necessarily each other. They can both be male, both female, or opposite sex.
"Hey Jill, I made your boyfriend Bill my bitch in prison."
Jill: "Oh cool, I guess that makes us eskimo siblings!"
Jill: "Oh cool, I guess that makes us eskimo siblings!"
by KateMinus8 May 3, 2014

Two people who happen to be dating and also happen to look like they are siblings; generally greeted with fear and disgust. Normally they are made fun of by people who have no idea who they are but see them 'macking' on each other in public.
Extra Points: They dress similarly. They have similar names. They randomly have the same last name and/or they are actually siblings.
Extra Points: They dress similarly. They have similar names. They randomly have the same last name and/or they are actually siblings.
"In the long run it's a good thing you and Fredrick didn't go out, because you would be one of those gross sibling couples."
Sibling couples awk me out!
Sibling couples awk me out!
by PDA Policeman # 31276 November 20, 2009

Siblings whom have only one common parent whether it's their mother or their father. Half-siblings sometimes are raised together, but more commonly raised in their two separate families. Half-siblings are typically separated and have somewhat distant relationships, when not raised together which is very common. If you have half-siblings, you call them brother, sister, not "half", or you call them nothing....
by exploding air plane 6969 August 30, 2017

A day to give your sibling(s) some love! Give them a gift or simply just tell them you appreciate them.
by you deserve everything May 9, 2020

The weekly holiday of calling your siblings on Sunday, no matter how far from one another, or not close you are to one another, simply to keep a connection, and possibly strengthen your lineage in case of a "Game of Thrones" and /or "Succession" scenario.
My sister told me about the subway bum that attacked her this week when I called her on Sibling Sunday
This Sibling Sunday we talked about gathering board seats to vote our father out as CEO
It was great to talk to my sister on Sibling Sunday this week, I cant remember the last time our mom talked to her brother.
My sister called me for Sibling Sunday and was disgusted with how hungover I was but still had a great talk.
Sibling Sunday is the best cause no matter how successful your sibling is they wont judge you
This Sibling Sunday we talked about gathering board seats to vote our father out as CEO
It was great to talk to my sister on Sibling Sunday this week, I cant remember the last time our mom talked to her brother.
My sister called me for Sibling Sunday and was disgusted with how hungover I was but still had a great talk.
Sibling Sunday is the best cause no matter how successful your sibling is they wont judge you
by GeorgetheGypsy January 18, 2023

Jessica used to be best friends with my sister, Taylor. After a few years she was tired of that and became my best friend. That sibling slut traded me in for Taylor the other day.
by Smurfarcher August 12, 2018

The feeling of obligation, loyalty, and affection, shared between persons who traditionally but not always share one or more parents, despite the terrible things they did to one another as children and sometimes to one another as adults.
Clara and Tony feel sibling love for Libby, even though, during childhood, Tony and Clara would use a television remote to convince Libby that she was invisible and mute.
by HappyWeddingLibby May 17, 2019
