(duopolies)
1.
If two companies or people have a ~ on something such as an industry, they share complete control over it and it is impossible for others to become involved in it. (BUSINESS)
They are no longer part of a ~ on overseas routes.
N-VAR
2.
A ~ is a group of two companies which are the only ones which provide a particular product or service, and which therefore have complete control over an industry. (BUSINESS)
Their smaller rival is battling to end their ~.
N-COUNT