Definition of polar line in US English:

polar line

noun

  • 1A line passing through a pole or related to a (geographic or magnetic) pole; especially a line joining north and south magnetic poles.

  • 2Geometry= "polar".

Origin

Mid 17th century (in an earlier sense). From polar + line.

Pronunciation

polar line

/ˌpəʊlə ˈlʌɪn/