IPA: /ɪnˈsʌpərtəbli/
KK: /ɪnˈsʌpərtəbli/
In a way that cannot be supported or tolerated; excessively or unbearably.
The noise from the construction site was insupportably loud, making it hard to concentrate.
Insupportably → It is formed from "in-" (meaning not), "support" (from Latin "supportare", meaning to carry or bear), and "-ably" (meaning in a manner). The word "insupportably" means in a manner that cannot be supported or endured.
Think of 'not' ('in-') being able to 'bear' ('support') something, which helps you remember that 'insupportably' means something that cannot be endured.