mesopelagic adjective 1noun 1forms 1 adjective1 •Describing the pelagic zone of the ocean between the photic epipelagic and the aphotic bathypelagic zones, characterized by very minimal light.For those animals living in the mesopelagic zone, where some light downwells from the surface, a visual predator looking up at them could see a silhouette. — 2001 noun1 •A mesopelagic fish formsmesopelagics
