What is the meaning of Eco-?

ecology or the environment (in the ecological sense)

economy

eco- (forming words concerning ecology or the environment)

echo- (forming words related to echos or other reflected waves)

eco-

forms words relating to echos

eco- (environmental)

eco- (concerning ecology or the environment)

eco-; forms words concerning ecology or the environment

forms words relating to echos or other reflected waves

Source: wiktionary.org