Demersion :: Demersion (n.) The act of plunging into a fluid; a drowning.
Demersion :: Demersion (n.) The state of being overwhelmed in water, or as if in water..
Emersion :: Emersion (n.) The act of emerging, or of rising out of anything; as, emersion from the sea; emersion from obscurity or difficulties..
Emersion :: Emersion (n.) The reappearance of a heavenly body after an eclipse or occultation; as, the emersion of the moon from the shadow of the earth; the emersion of a star from behind the moon..