Definition of isobar in English:


Syllabification: i·so·bar
Pronunciation: /ˈīsəˌbär


1 Meteorology A line on a map connecting points having the same atmospheric pressure at a given time or on average over a given period.
More example sentences
  • Secret Meteorological Office charts show the alarming swirl of isobars converging in black lines over the Channel.
  • The tight spacing of the isobars indicates strong northerly winds, averaging some 50 km/h over much of Victoria.
  • When isobars on a weather chart are close together, it will be a blustery day…
1.1 Physics A curve or formula representing a physical system at constant pressure.
More example sentences
  • The heating isobar for the transformed monolayers remained virtually superimposable on the curve for films that had experienced no rapid compression.
  • No discontinuous change occurs in either the compression isotherm or the heating isobar.
  • For the heated film, the substantial reversion of the transformed film to the original behavior occurred without any discontinuous change in area or in the slope of the heating isobar.
2 Physics Each of two or more isotopes of different elements, with the same atomic weight.


mid 19th century: from Greek isobaros 'of equal weight', from isos 'equal' + baros 'weight'.



Pronunciation: /ˌīsəˈbarik, -ˈbär-/
More example sentences
  • A phase transition produced by isothermally increasing surface pressure can often be reversed during isobaric heating.
  • This diagram is the same as the one above except that the major pressure and wind zones have been replaced by a typical isobaric weather map.
  • For all simulations, isothermal and isobaric conditions were assumed.

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