What' s the piont of that small hole on the side of some bathroom sinks??

Question

I just noticed that my bathrooom sink has a small penny-sized hole on the left side of my bathroom sink. I just wanted to know what's it for.

Thanks a lot ;)

Answer 1

It's incase it overflows. It'll suck some of the water down. It also helps with the air flow in the pipes. The water won't go down otherwise.

Answer 2

Air pressure. To let water flow out of basin.

Answer 3

It allows the water to drain before the sink starts overflowing.

Answer 4

in case it overflows

Answer 5

to help prevent overflow

Answer 6

overflow

Answer 7

if the water overflows the hole will drain it.

same with bath tubs.

Answer 8

just incase it overflows