Backslash

That one annoying key that always gets pressed trying to hit enter or backspace.\

James: Hi!\
Andy: What's with that backslash?
James: Oh, I hit that stupid annoying key while trying to hit enter.\
James: OMG I DID IT AGAIN.
Andy: It's alright, everyone does it.\

backslashing

Fucking somebody from behind diagonally in bed

Dude, we were backslashing so hard last night I almost fell out of bed.

Backslashing

To troll someone or annoy them.

You can Backslash someone in public or privately
Ex: Im gonna backslash you
Ex 2: Stop backslashing