The Collaborative International Dictionary
Demersion
Demersion \De*mer"sion\n. [L. demersio.]
The act of plunging into a fluid; a drowning.
The state of being overwhelmed in water, or as if in water.
--Ray.
Wiktionary
demersion
n. 1 The act of plunge into a fluid; a drowning. 2 The state of being overwhelmed in water, or as if in water.