A collier is also an occupational title for people who carried and sold coal. In the Middle Ages colliery was a common profession.
The profession is mentioned in the opening scene of Romeo & Juliet, as the two servants Gregory and Sampson joke about that they shall not carry coal, or else they shall be colliers.
Collier Row, a place in the London Borough of Havering.
Colliers Wood is an area in the London Borough of Merton.
Collier's was a magazine published between 1888 and 1957.