North Sea 
An arm of the Atlantic Ocean lying between the mainland of Europe and the coast of Britain, important for its oil and gas deposits.
- prole
- proleg
- pro-legate
- prolegomenal
- prolegomenary
- prolegomenist
- prolegomenon
- prolegomenous
- prolepsis
- proleptic
- proleptical
- proletaire
- proletarian
- proletarianisation
- proletarianism
- proletarianization
- proletarianize
- proletarianly
- proletarian revolution
- proletariat
- proletariate
- proletariatism
- proletarisation
- proletarise
- proletarization