occupation grunt
A loud, rude noise made by someone in a men's room stall when they hear another guy walk in. It's like a warning that says, 'Don’t even think about opening this door.'
'I'm still in here, and I'm not done yet!' he bellowed.
'If you try to open that door, I'll come out and punch you.'
'You better not try to open this door, or I'll come out and beat you up.'