(1):

(v. t.) To throw (something) over a thing so as to cover it.

(2):

(v. t.) Fig.: To cover completely, as if with water; to immerse; to overcome; as, to whelm one in sorrows.

(3):

(v. t.) To cover with water or other fluid; to cover by immersion in something that envelops on all sides; to overwhelm; to ingulf.