Gaian /ˈɡaɪ.ən/noun 3adjective 1forms 3 noun3 •An inhabitant of Earth. •(Internet) A member of the anime-themed social networking and forums-based website Gaia Online.Inspired by comic-book and anime fans, “Gaians” play games, […] — 2008 •A radical Green who views the ecology of the Earth's biosphere not only as the basis of human moral examples, but of all cognition and even sentience. adjective1 •Of or relating to Gaia. formsGaians · more Gaian · most Gaian