ology

Ology is a suffix in English used to name a branch of knowledge or the study of a particular subject. It derives from the Greek -logia, meaning “the study of” or “the science of,” via Latin, and is attached to a wide range of stems to form nouns such as biology, geology, meteorology, archaeology, and psychology.

Fields formed with -ology usually indicate systematic inquiry and knowledge about a domain. Biology studies life, geology the Earth, meteorology the atmosphere, archaeology past human activity, and psychology mind and behavior. The presence of -ology signals scholarly study, but it does not by itself determine a field’s methods; some -ology terms describe humanities or religious studies as well, such as mythology or theology.

The -ology suffix is highly productive in naming disciplines and often expands as knowledge grows. New ologies arise in interdisciplinary contexts or from advances in science and technology, including ecology, neurobiology, and sociolinguistics. While many -ologies denote empirical sciences with observable methods, others refer to theoretical, interpretive, or applied areas of study. Overall, -ology serves as a flexible label for organized bodies of knowledge and inquiry.