Isotherm

[aisәuθә:m]

Definition

(noun.) (meteorology) an isogram connecting points having the same temperature at a given time.

Edited by Colin--From WordNet

Definition

(n.) A line connecting or marking points on the earth's surface having the same temperature. This may be the temperature for a given time of observation, or the mean temperature for a year or other period. Also, a similar line based on the distribution of temperature in the ocean.

Edited by Everett