| Noun | 1. | environmentalism - the philosophical doctrine that environment is more important than heredity in determining intellectual growthphilosophical doctrine, philosophical theory - a doctrine accepted by adherents to a philosophy hereditarianism - the philosophical doctrine that heredity is more important than environment in determining intellectual growth |
| 2. | environmentalism - the activity of protecting the environment from pollution or destruction preservation, saving - the activity of protecting something from loss or danger |