To move through the water, without touching the bottom; to propel oneself in water by natural means.

To become immersed in, or as if in, or flooded with, or as if with, a liquid

“a bare few bits of meat swimming in watery sauce”

To move around freely because of excess space.

To be dizzy or vertiginous; have a giddy sensation; to have, or appear to have, a whirling motion.

“My head was swimming after drinking two bottles of cheap wine.”