n. [ Iso- + Gr. &unr_; cold. ] (Phys. Geog.) A line connecting points on the earth's surface having the same mean temperature in the coldest month of the year. [ 1913 Webster ]
The Collaborative International Dictionary of English (GCIDE) v.0.53Collaborative International Dictionary (GCIDE)
n. [ Iso- + Gr. &unr_; cold. ] (Phys. Geog.) A line connecting points on the earth's surface having the same mean temperature in the coldest month of the year. [ 1913 Webster ]