Definition of "unbearable"
adjective
comparative more unbearable, superlative most unbearable
So unpleasant or painful as to be unendurable.
Quotations
The heat of the fire, the steam which arose from the dampening water, the hard slogging at the white-hot metal of the links, and the continual pulling of lengths of chain, were calculated to put a test on the strongest of men, and often on hot summer days they had to be sent home, for the work became unbearable.
1945 January and February, A Former Pupil, “Some Memories of Crewe Works—III”, in Railway Magazine, page 14