The Collaborative International Dictionary
isobare
Isobar \I"so*bar\, n. [Iso- + Gr. ? weight.] (Phys. Geog.) A line connecting or marking places upon the surface of the earth where height of the barometer reduced to sea level is the same either at a given time, or for a certain period (mean height), as for a year; an isopiestic line. [Written also isobare.]