in- ‘not’ + tolerabilis (see tolerable)

source: [Steam コミュニティ :: :: Rage Intensifies]

unable to be endured:

〈痛み･緊張などが〉我慢できない, 耐えられない(unbearable)(↔ tolerable)

e.g. the intolerable pressures of his work.

intolerably |inˈtäl(ə)rəblē, inˈtälərblē| adverb

intolerability |-ˌtälərəˈbilitē| noun

intolerableness |inˈtäl(ə)rəb(ə)lnəs| noun

late Middle English: from Old French, or from Latin intolerabilis, from in- ‘not’ + tolerabilis (see tolerable).