Dictionary entry

Isotherm

Webster's Dictionary 1913

I″so‐therm (?), n. [Iso- + Gr. � heat, fr. � hot.] (Phys. Geog.) 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.