Impossible to tolerate or endure; unbearable.
Not tolerable; unbearable; too severe, painful, cruel, etc. to be endured.
The definition of intolerable is something that is unbearable or not able to be endured.
When pain is too much to bear or cope with, this is an example of a time when the pain would be described as intolerable.
Origin of intolerable
From Middle French intolerable, from Latin intolerabilis