IPA: /ʌnˈbɛrəbli/
KK: /ʌnˈbɛrəbli/
In a way that is too difficult or painful to endure.
The heat was unbearably intense during the summer.
Unbearably → It is formed from "un-" (meaning not) and "bear" (from Old English "beran", meaning to carry or endure) and "-ably" (meaning in a manner that can be). The word "unbearably" means in a manner that cannot be endured or carried.
Think of 'not' ('un-') being able to 'carry' or 'endure' something ('bear') — that's why 'unbearably' means something that is too difficult to endure.