When they say on the razor's edge, does it mean sharp, or smart?

Question

When they say on the razor's edge, does it mean sharp, or smart?

Answer 1

it could mean very up to date, but usually it means a difficult choice.

Answer 2

It means you trolls need to get out of the Ramadan section.

Answer 3

It means dont fall str8 down. jump to the left or right