pelagic (adj.) Look up pelagic at Dictionary.com
"pertaining to the sea," 1650s, from Latin pelagicus, from Greek pelagikos, from pelagos "sea, high sea, open sea, main," from PIE *pelag- "to spread out" (source of Greek plagos "side," Latin plaga "hunting net, curtain, region"), possibly from root *plak- (1) "to spread out, be flat" (see placenta).