i·so·therm
noun/ˈaɪsəθɜːm/
/ˈaɪsəθɜːrm/
(specialist)- a line on a weather map that joins places that have the same temperature at a particular time
（天气图上的）等温线 Word Originmid 19th cent.: from French isotherme, from Greek isos ‘equal’ + thermē ‘heat’.