unionism

Belief in or support for a union or unions, especially a labor union or labor unions generally.

The principles, theory, or system of a union or unions, especially a labor union or labor unions generally.

The principle or theory of forming a union.

The principles, theory, or system of a union, especially a trade union.

Loyalty to the United Kingdom, especially in support of its sovereignty over Northern Ireland.

Loyalty to the federal government of the United States during the Civil War.

The principle of uniting or combining; specifically, trade-unionism.

Attachment or loyalty to the principle of union, or to some particular union; specifically, attachment or loyalty to the federal union known as the United States of America, and opposition to its rupture, as by the secession of the Southern States in 1861-5.