Longman Dictionary of Contemporary English
eco-
prefix
EXAMPLES FROM OTHER ENTRIES
▪ eco-education
▪ eco-friendly agriculture
▪ eco-toys
▪ Activist want the government to invest in low-impact eco-tourist facilities.
▪ Officials see a role for sophisticated eco-technology to help eradicate pollution sweeping across the region.
Douglas Harper's Etymology Dictionary
eco-
word-forming element referring to the environment and man's relation to it, abstracted from ecology, ecological; attested from 1969.
Wiktionary
eco-
pre. 1 ecology or the environment (in the ecological sense) 2 economy