Demersion

De·mer'sion noun [ Latin demersio .] 1. The act of plunging into a fluid; a drowning. 2. The state of being overwhelmed in water, or as if in water. Ray.
Found on http://www.encyclo.co.uk/webster/D/32

Demersion

• (n.) The state of being overwhelmed in water, or as if in water. • (n.) The act of plunging into a fluid; a drowning.
Found on http://thinkexist.com/dictionary/meaning/demersion/
No exact match found