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.
- polyarthritic
- polyarthritis
- polyarticular
- polyatomic
- polyautography
- polyaxial
- polybag
- polybase
- polybasic
- polybasicity
- polybasite
- Polybius
- polyblast
- polyblastic
- polyblend
- polybranchiate
- polybrominated
- polybrominated biphenyl
- polybutadiene
- polybutylene
- polycarbonate
- polycarboxylate
- polycarboxylic
- polycarpellary
- polycarpic