The word Unionist, simply meaning one espousing a union, has a number of connotations, depending on context:

• Unionists are people in Ireland, England, Scotland and Wales who were historically in favour of uniting their nations into a United Kingdom, or who in modern times wish their nations to remain part of the United Kingdom.
• For greater detail on Unionists in Ireland see the article Unionists (Ireland); for greater detail on Unionists in Scotland see Unionists (Scotland) and Conservative Party (UK) (the full name of which is the Conservative and Unionist Party).
• Members and supporters of trades unions also bear the label of unionists.
• Unionist is also a term used to describe someone loyal to the Union Forces during the American Civil War. For greater detail on American Unionists see the article Unionists (American).
• The Unionist Party (Canada) was a merger of parties that led Canada during WWI.