What's the meaning of this sentence?
have you ever been low?
In inquiry as to if you've ever been depressed or feeling sad.
Low is a slang term for sadness or depression. So the sentence is saying "have you been sad (or depressed) lately?"
Low means sad. So: Have you ever been sad?
There are 3 kinds of lows 1 . Close to ground 2. Like answers above 3. Ignorant, if you use it in a sentence " you're so low" it's a term of being very bad beyond belief