Submerge

[Sarah]

To plunge into water or other fluid; to be buried or covered,as by a fluid; to be merged; hence, to be completely included.Some say swallows submerge in ponds. Gent. Mag.

[Sarah]

To go down on somebody after you already have; to eat someone out

[Greta]

Cause (something) to be under water.

[Dorothey Allen]

to go below or make something go below the surface of the sea or a river or lake:

[Donald Trump]

Cause to be under water.