The term for the study of the origins and historical development of words is etymology.
Etymologists investigate how a word’s form and meaning change over time. They compare older documents, dialects, related languages, and patterns of sound change to reconstruct a word’s history. A word may be inherited from an earlier form, borrowed from another language, created through compounding or derivation, or shaped by imitation of a sound.
The word “etymology” comes from Ancient Greek roots associated with “true” or “real” meaning and the study of words. Ancient Indian, Greek, Arabic, and European scholars all developed traditions of explaining word origins, though many early explanations relied on imaginative sound resemblances rather than systematic evidence.
Etymology is not the same as semantics, which examines meaning, or morphology, which studies word structure. It also does not necessarily reveal a word’s original or “true” meaning: meanings can shift dramatically, and popular origin stories are often false. Modern etymology became more rigorous alongside comparative historical linguistics in the 18th and 19th centuries.