Is Overwhelmingness a Word?

The property of being overwhelming.

Is there such a word as Overwhelmingness?

adj. Overpowering in effect or strength: overwhelming joy; an overwhelming majority. o′ver·whelm′ing·ly adv.

Is there a noun form of overwhelm?

So it comes as something of a surprise to learn that “overwhelm” has been a noun since at least 1596, according to the Oxford English Dictionary. The definition given, “[t]he action of overwhelming; the fact or state of being overwhelmed; an instance of this,” is the way it is still being used today.