treasonously

As a noun taxonomy

is the science or the technique used to make a classification.

As an adverb treasonously is

in a treasonous manner, or to a treasonous degree.

Treasonously is a synonym of treasonably.

As adverbs the difference between treasonously and treasonably

is that treasonously is in a treasonous manner, or to a treasonous degree while treasonably is in a treasonable manner.

As an adjective treasonous

is like or in the way of treason.

As an adverb treasonously is

in a treasonous manner, or to a treasonous degree.