Besterday 

The day before yesterday

I think I got concussed besterday

Besterday by Ulla Inga April 14, 2015

besterday 

The previous business day, exluding weekends, holidays, and vacation days.

Boss: Did you send me those reports?
Employee: Check the bottom of you mail folder, I sent them besterday!?!

besterday by Alberto Weinsenstein December 24, 2010

Yesterday X Separation

Yesterday X Separation (Korean: 옛델대 뷔 셉알앋이온, stylized YESTERDAY / SEPARATION), commonly known as YXS, is a five-member Kwangyanese boy band formed by Throw It Back Rosie Entertainment. The group consists of five members Stoove, Yeoniel, Bengyu, Taerry and Kaimal.

Naega Byeonhae by Yesterday X Separation outsold the whole K-Pop Industry.

Yesterday X Separation by jenlisaforever January 26, 2022

2 of 'em Yesterday 

A business term meaning you want Lots of them as soon as possible.

"2 of 'em" refers to the item and means you want lots of the item.

"Yesterday" means as soon as possible.

We need those clothes fast. 2 of 'em Yesterday!

2 of 'em Yesterday by TheGymRat February 27, 2019

Befesterday 

the day before yesterday
before + yesterday = befesterday

Robert: I really wish I can describe how I felt hanging out with you... not yesterday, but the day before yesterday.
Mia: You mean befesterday?
Robert: Wow, what a genius, concise word that the English Language does not have yet...

Befesterday by Me-Mover May 14, 2019

Yesterday's Gravy 

Old news; something that has fallen out of trend

Stranger 1: "Hey! Did you hear about that movie that came out last Friday?!"

Stranger 2: "That's yesterday's gravy bro."

Yesterday's Gravy by Hellbound Harry March 30, 2015

I'll call you yesterday 

A sarcastic phrase used to signify that you actually won't call or interact with someone in the future. The phrase implies that you would have theoretically called them "yesterday" if you really cared. This phrase is primarily used a means of blowing someone off.

Jim: So did you meet up with that girl you got coffee with last week?

Nick: Nah, she blew me off and never texted back after. It was an "I'll call you yesterday" type of situation.

I'll call you yesterday by FrenchOnion May 18, 2020