Looking for a quick definition?
We’ve got loads of key subject terms in our subject glossaries. There are three ways of finding what you are looking for:
- First click on the letters of the alphabet to browse for terms.
- Select a subject from the drop-down menu above to filter the terms by Subject.
- Or lastly, type the term you are looking for into the search box.
Here are some examples of the kinds of definitions you’ll find on this page.
the seepage of acidic, contaminated water from disused mines and mine dumps.
rain that contains high levels of sulfuric acid, hydrochloric acid and nitric acid.
animals that lack a cavity between the digestive tract and the outer body wall.
a disease caused by the human immunodeficiency virus (HIV).