isobar (n.)youdaoicibaDictYouDict[isobar 词源字典]
1864, coined from Greek isos "equal" (see iso-) + baros "weight," from PIE root *gwere- (2) "heavy" (see grave (adj.)). Line connecting places with the same barometric pressure at the same time.[isobar etymology, isobar origin, 英语词源]