unionism

noun

1. the principle of union, especially trade unionism.
2. attachment to a union.
3. (initial capital letter) loyalty to the federal union of the United States of America, especially at the time of the Civil War.

noun

1. the principles of trade unions
2. adherence to the principles of trade unions
3. the principle or theory of any union

noun

1. (sometimes not capital) the principles or adherence to the principles of Unionists