Assumingly is an adverb. The adverb is an invariable part of the sentence that can change, explain or simplify a verb or another adverb.

What is the verb of assumption?

assume. To authenticate by means of belief; to surmise; to suppose to be true, especially without proof. To take on a position, duty or form. To adopt a feigned quality or manner.

Is Takea a verb?

verb (used with object), took, tak·en, tak·ing. to get into one's hold or possession by voluntary action: to take a cigarette out of a box; to take a pen and begin to write. to hold, grasp, or grip: to take a book in one's hand; to take a child by the hand.