(yn′yən·ist) noun
1. An advocate of union or unionism.
2. A member of a trade union.

(yn′yən·ist) noun
1. One who before and during the Civil War in the United States supported the Union cause and opposed secession; a Union man.
2. One of those opposed to loosening the formal ties between Great Britain and Ireland, whether belonging to the Conservatives or the branch of the Liberals (Liberal Unionists) that separated from their party in 1886 in opposition to the advocates of Home Rule for Ireland. From this time the term Unionists began to come into use, at first to signify both the Conservative and the Liberal Unionist parties, and later, as the distinction between the two wings gradually grew smaller, the Conservative Party.