If you google "bar sinister", you will get an array of various responses. There is Bar Sinister, "LA's #1 UnderGround NightClub in HOLLYWOOD Gothic, Industrial, AlternatiVe sound EVERY SATURDAY". Sounds like a happening place!
Then there is the concept of "bar sinister", an incorrect way to refer to "bend sinister" on a coat of arms, a diagonal sash that represents illegitimacy. It can also mean someone born out of wedlock. A bastard, simply.
And speaking of bastards, there is Simon Bar Sinister, the villain of Underdog cartoons from the 1960s. He is a mad scientist who is a parody of Lex Luthor, wants to take over the world (join the club!), and is always foiled by Underdog. Some wonder if he is Jewish because his name is a play on words of the heraldic bar sinister and... Jewish freedom fighter Simon bar Kokhba? (Let's use the Gargamel Law: Not a Jew.)
Now, to get to the cartoon character, you first must get through various photos associated with the aforementioned nightclub...
Don't google "bar sinister".