isobar
noun /ˈaɪsəbɑː(r)/
/ˈaɪsəbɑːr/
(specialist)- a line on a weather map that joins places that have the same air pressure at a particular time
（天气图上的）等压线 词源mid 19th cent.: from Greek isobaros ‘of equal weight’, from isos ‘equal’ + baros ‘weight’.