1) Agonizing 2) Awful 3) Bitter 4) Deplorable 5) Excessive 6) Excruciating 7) French word used in English 8) Horrendous 9) Impermissible 10) Impossible 11) Improper 12) Insufferable 13) Insupportable 14) Not tolerable 15) Objectionable 16) Offensive 17) Unacceptable 18) Unbearable 19) Undesirable 20) Unendurable 1) Beyond the pale 2) Hated 3) Horrible 4) Impermissible 5) Indefensible 6) Insufferable 7) Loathsome 8) Offensive 9) Unbearable 10) Unendurable 11) Unforgivable 12) Unsufferable 13) Unsupportable 14) Untolerable 
• (a.) Enormous. • (a.) Not tolerable; not capable of being borne or endured; not proper or right to be allowed; insufferable; insupportable; unbearable; as, intolerable pain; intolerable heat or cold; an intolerable burden.
In·tol'er·a·ble adjective [ French intolérable , Latin intolerabilis . See In- not, and Tolerable .] 1. Not tolerable; not capable of being borne or endured; not proper or right to be allowed; insufferable; insupportable; unbearable; as, intolerable pain;...
[adj] - impossible to tolerate or endure 2. [adj] - completely unacceptable
intolerable, intolerableness 1. Anything that is so bad, difficult, or painful that it cannot be endured: 'The pain was so intolerable that he could not sleep.' 2. Very unpleasant or terribly annoying. 3. Completely unacceptable.
living things cannot survive under this condition
unbearable adjective incapable of being put up with; `an intolerable degree of sentimentality`
not tolerable; unendurable; insufferable: intolerable pain. · excessive.