wallknocker

A wall-knocker is a parent in the next hotel room (for example, room 219 at the Hilton) who knocks on the wall to tell you to quiet down, because you’re having more fun than they are.

Even when you hear the knocks and stop talking loudly, they will call the front desk, and blame their unsettled baby on you being noisy, when really they just suck at putting their kid to bed but want someone to blame besides themselves because they’re dissatisfied and miserable.