Why do you say "square" in "Be there or be square"? [closed]
Solution 1:
square: conventional, boring.
(slang) A socially conventional person; typically associated with the 1950s
Why do you always wear a tie? Don't be such a square!
be there or be square:
(idiomatic, US, UK, humorous) Used to encourage someone to go somewhere.
There's a huge party on Saturday night; be there or be square.