The study of all living things, especially their origins, evolution and interrelationships.
A treatise or similar work that summarizes the known facts of either of the above.
The progression of a medical condition in an individual.
The study of all natural phenomena: botany, zoology, mineralogy, etc.
A branch of biology that deals with the functions and activities of life or of living matter (as organs, tissues, or cells) and of the physical and chemical phenomena involved.