isopor

[ahy-suh-pawr]

noun

an imaginary line on the earth's surface connecting points of equal annual change in the declination, inclination, or other components of the earth's magnetic field.

Origin of isopor

1930–35; iso- + -por < Greek póros path, pore²

Also called isoporic line.

Related formsi·so·por·ic, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018