1.
Ecological means involved with or concerning ecology.
Large dams have harmed Siberia’s delicate ~ balance.
ADJ: ADJ n
~ly
It is economical to run and ~ly sound.
ADV
2.
Ecological groups, movements, and people are concerned with preserving the environment and natural resources, so that they can be used in a sensible way, rather than being wasted.
Ecological groups say that nothing is being done to tackle the problem.
ADJ: ADJ n