isopag

[ ahy-suh-pag ]
/ ˈaɪ səˌpæg /

noun

a line drawn on a map connecting all points where ice exists at approximately the same period during winter.

Origin of isopag

iso- + -pag < Greek págos frost
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019