Ecological (adjective)

1. Relating to the study of the relationships between organisms and their environment.
2. Relating to the relationship between living organisms and their environment.

Origin:

From greek οἶκος (oîkos, "house") + -λογία (-logia, "study of"), from the root of λόγος (lógos, "word, reason") and λόγος (lógos, "study").

Examples:

1. The ecological impact of the oil spill was severe.
2. He studies ecological systems.
3. The ecological balance of the ecosystem is important.
4. The ecological footprint of the factory is too large.
5. The development must be done in an ecological way.