DDT (Dichlorodiphenyltrichloroethane): A synthetic insecticide used widely from WWII until it was banned in many countries from 1970s due to its harmful impact on wildlife detailed in 'Silent Spring'.
Bioaccumulation: The accumulation of substances, such as pesticides or other chemicals in an organism. This concept is key to understanding some arguments made in 'Silent Spring'.
Ecology: The branch of biology which studies interactions among organisms and their environment. It provides context to many observations made in 'Silent Spring'.