en ‧ vi ‧ ron ‧ men ‧ tal ‧ ist AC /ɪnˌvaɪrənˈment ə ləst, ɪnˌvaɪrənˈment ə lɪst/ BrE AmE noun [countable]
[ Word Family: noun : ↑ environment , ↑ environmentalist ; adverb : ↑ environmentally ; adjective : ↑ environmental ]
someone who is concerned about protecting the environment