Based is used to describe someone from "Base Reality" - It comes from the conflicting theories of if we are living in a "Base Reality" or a "Simulation". The concepts of differing realities (matrix style) gained traction after Elon Musk made the following statements:
1.) From the Recode Code Conference (2016) There is “a one in billions chance that this that is the world in which we live is base reality.” Which is to say, not a simulation.
2.) From the Joe Rogan Experience Podcast (2018): "Why would you make a simulation that's boring? You'd make a simulation that's way more interesting than base reality," Musk said.
A base reality is the idea that there are multiple layers of reality - and those who are from base reality or are "based" (usually associated with common sense and critical thinking) are living with those from a simulation or parallel reality/timeline.
1.) From the Recode Code Conference (2016) There is “a one in billions chance that this that is the world in which we live is base reality.” Which is to say, not a simulation.
2.) From the Joe Rogan Experience Podcast (2018): "Why would you make a simulation that's boring? You'd make a simulation that's way more interesting than base reality," Musk said.
A base reality is the idea that there are multiple layers of reality - and those who are from base reality or are "based" (usually associated with common sense and critical thinking) are living with those from a simulation or parallel reality/timeline.
by Terra Luna May 5, 2022
Get the Basedmug. Slang: Agreement with a regressive opinion to try to fit in with a crowd. Could be read as short for 'Based on conformity'. The polar opposite of punk.
May have had a different slang definition originally, but this has what it has become through online usage.
May have had a different slang definition originally, but this has what it has become through online usage.
Punk:
Living your life your own way giving no fucks what people think = That's punk.
"Based":
Moron 1: ""Hitler had the right idea""
Moron 2: "That's based, bro."
Living your life your own way giving no fucks what people think = That's punk.
"Based":
Moron 1: ""Hitler had the right idea""
Moron 2: "That's based, bro."
by ShadowBlaze January 9, 2023
Get the Basedmug. caden: I got so lucky last night
newt:bbbbroooo 3rd base?!?
caden: no 222th base ;)
newt : you sick bastard
newt:bbbbroooo 3rd base?!?
caden: no 222th base ;)
newt : you sick bastard
by liberal bug September 8, 2020
Get the 222th basemug. 
A emo player that cares about the game and they have barcodes on there wrist thats what a base player is
by Atasui August 12, 2021
Get the Base playermug. by theonlyheartless January 12, 2012
Get the muffin basemug.