Share this entry
isobar Syllabification: i·so·bar
Pronunciation: /ˈīsəˌbär/

Definition of isobar in English:


Image of isobar
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.
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.
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.


Pronunciation: /ˌīsəˈbärik/
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  • This diagram is the same as the one above except that the major pressure and wind zones have been replaced by a typical isobaric weather map.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.


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

Definition of isobar in:
Share this entry

What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.

Subscribe to remove ads and access premium resources