Bye-election

a special election, not held at the time of a general election, to fill a vacancy in Parliament.
Historical Examples

The Master of Mrs. Chilvers Jerome K. Jerome
Reminiscences of Queensland William Henry Corfield
The Testing of Diana Mallory Mrs. Humphry Ward
The Grey Wig: Stories and Novelettes Israel Zangwill
Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 3 Various
The Testing of Diana Mallory Mrs. Humphry Ward
Fifteen Chapters of Autobiography George William Erskine Russell
The Great North Road: York to Edinburgh Charles G. Harper
The New Machiavelli Herbert George Wells
Handbook of Home Rule (1887) W. E. Gladstone et al.

noun
(in the United Kingdom and other countries of the Commonwealth) an election held during the life of a parliament to fill a vacant seat in the lower chamber
(in the US) a special election to fill a vacant elective position with an unexpired term

Read Also:

Byes
near to or next to: a home by a lake. over the surface of, through the medium of, along, or using as a route: He came by the highway. She arrived by air. on, as a means of conveyance: They arrived by ship. to and beyond the vicinity of; past: He went by the church. […]
Byelaw
bylaw. a standing rule governing the regulation of a corporation’s or society’s internal affairs. a subsidiary law. British. an ordinance of a municipality or community. noun a rule made by a local authority for the regulation of its affairs or management of the area it governs a regulation of a company, society, etc a subsidiary […]
Byelgorod-dnestrovski
noun a variant spelling of Belgorod-Dnestrovski

Byelorussia
Official name Belarus. Formerly White Russian Soviet Socialist Republic, Byelorussian Soviet Socialist Republic. a republic in E Europe, N of Ukraine: formerly a part of the Soviet Union. 80,154 sq. mi. (207,600 sq. km). Capital: Minsk. a region in the W part of former czarist Russia. noun a variant spelling of Belarus
Byelorussian
of or relating to Byelorussia, its people, or their language. a native or inhabitant of Byelorussia. an East Slavic language, spoken by the inhabitants of Byelorussia and written in the Cyrillic alphabet. Compare Slavic (def 1). adjective, noun a variant spelling of Belarussian