(Latin: suffix; able manner, capably)

Forming adverbs corresponding to adjectives in -able.

treasonably (adverb), more treasonably, most treasonably
Acting in a manner or style that is disloyal, faithless, and a betrayal of allegiance: Matthew was behaving in a treasonably odd manner that made people wonder if he was doing something illegal and disloyal to his family.
unaccountably (adverb)
1. In an unaccountable manner.
2. For some unknown and usually puzzling reason.
3. Not able to be explained or understood: "His father said that he felt unaccountably good when he got up this morning."
unalterable (adjective), more unalterable, most unalterable
A reference to something that is incapable of being changed or modified: There is an unalterable season of bitter cold during a Siberian winter.
unamiably (adverb), more unamiably, most unamiably
unappeasably (adverb)
A descriptive word for not capable of being appeased, significantly changed, or mitigated.
unavoidably (adverb), more unavoidably, most unavoidably
1. A description of that which can not be prevented nor ignored: The visitors to Eugene's home were unavoidably delayed in arriving as they had planned because of the heavy traffic on the streets.
2. A reference to a situation or conditions which are certain to happen: When strong cyclones or tornadoes take place, there are usually certain to be unavoidably severe electrical outages, travel accidents, etc.
uncharitable (adjective), more uncharitable, most uncharitable
1. Lacking love and generosity.
2. Harsh and severe.
3. Unfair or unkind: Why did Mary make such uncharitable remarks about Sam's failure to achieve the tennis championshiip?
unconquerably (adverb), more unconquerably, most unconquerably
In a manner that cannot be defeated, subdued, or overpowered: Jack's unconquerably good humor could not be surpassed by the sudden snowstorms.
undeniably (adverb); more undeniably, most undeniably
Descriptive of how something is admitted to be clearly true; indisputably: Sharon is undeniably considered to be the best piano player of her time.
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!
1. To an unimaginable extent; unthinkably.
2. Totally unlikely.