undurably
/ˈʌndərəbli/Definitions
1. adverb
in a way that cannot be borne or endured; intolerably
“The noise was coming from the construction site and was being produced undurably loud by the jackhammers.”
2. adverb
in a way that cannot be supported or sustained; impractically
“The team was forced to abandon the project due to its undurably high costs and complex implementation.”