weil

Weil is a German-language term that functions as a surname, a place-name element, and, in lower-case, as a common German conjunction meaning “because.” As a surname and toponym, Weil largely derives from Germanic place-name traditions associated with settlements.

Notable people bearing the surname include André Weil (1906–1998), a French mathematician and a key member of the Bourbaki group. Weil made significant contributions to algebraic geometry, number theory, and topology, and several mathematical concepts bear his name, including the Weil conjectures.

As a geographic name, Weil appears in several German towns and city districts. Examples include Weil am Rhein in Baden-Württemberg, located near the Swiss and French borders, and Weil der Stadt, also in Baden-Württemberg. The element Weil is found in other place names across German-speaking regions, typically indicating historical settlement origins.

Etymologically, the surname and place names are tied to toponymy related to settlements or hamlets, reflecting the historical linking of families or places to a specific locality. In modern German, weil is the subordinating conjunction meaning “because.” It introduces causal clauses and typically sends the finite verb to the end of the clause, as in Ich bleibe zu Hause, weil es regnet.