1873, oecology, "branch of science dealing with the relationship of living things to their environments," coined in German by German zoologist Ernst Haeckel as Ökologie, from Greek oikos "house, dwelling place, habitation" (from PIE root *weik- (1) "clan") + -logia "study of" (see -logy). In use with reference to anti-pollution activities from 1960s.
word-forming element referring to the environment and man's relation to it, abstracted from ecology, ecological; attested from 1969.
Proto-Indo-European root meaning "clan, social unit above the household."
It forms all or part of: antoecian; bailiwick; Brunswick; diocese; ecology; economy; ecumenical; metic; nasty; parish; parochial; vicinage; vicinity; viking; villa; village; villain; villanelle; -ville; villein; Warwickshire; wick (n.2) "dairy farm."
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit visah "house," vit "dwelling, house, settlement;" Avestan vis "house, village, clan;" Old Persian vitham "house, royal house;" Greek oikos "house;" Latin villa "country house, farm," vicus "village, group of houses;" Lithuanian viešpats "master of the house;" Old Church Slavonic visi "village;" Gothic weihs "village."
c. 1400, "vegetables;" 1690s, "freshly cut branches used for decoration," from green (n.). Meaning "ecology political party" first recorded 1978, from German die Grünen (West Germany), an outgrowth of Grüne Aktion Zukunft "Green Campaign for the Future," a mainly anti-nuclear power movement, and/or grüne Listen "green lists" (of environmental candidates). Green (adj.) in the sense of "environmental" is attested in English from 1971; Greenpeace, the international conservation and environmental protection group, is from 1971.