What is "whelms"

Usage examples of "whelms".

I will lie awake for hours on end, incessantly checking my watch, plumping and punching my pillow, thrashing and turning on my mattress as if wrestling a foe, before sleep at last whelms over me only to subside a minute later when I am disturbed by the slightest noise or provoked by the jagged shard of an unremembered dream.

First of all the force of the wind when aroused beats on the harbours and whelms huge ships and scatters clouds.