You searched for: “most unendurably
unendurably (adverb), more unendurably, most unendurably
Pertaining to how something proceeds in an unpleasant or an intolerable way: Mrs. Jackson couldn’t put up with the unendurably obnoxious behavior of the student any longer and so she sent him to the principal’s office!
This entry is located in the following units: -ably (page 13) duro-, dur-, dura- (page 3)