Definition of isobar in English:

isobar

noun

  • 1Meteorology
    A line on a map connecting points having the same atmospheric pressure at a given time or on average over a given period.

    • ‘When isobars on a weather chart are close together, it will be a blustery day…’
    • ‘The balance of forces is lost and the flow crosses the isobars (lines of equal air pressure) towards the low pressure.’
    • ‘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.’
    • ‘Near the ground the winds are deflected across the contours, or isobars, towards the low pressure, due to friction.’
    1. 1.1Physics
      A curve or formula representing a physical system at constant pressure.
      • ‘The heating isobar for the transformed monolayers remained virtually superimposable on the curve for films that had experienced no rapid compression.’
      • ‘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.’
      • ‘No discontinuous change occurs in either the compression isotherm or the heating isobar.’
  • 2Chemistry
    Each of two or more isotopes of different elements, with the same atomic weight.

Origin

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

Pronunciation:

isobar

/ˈʌɪsə(ʊ)bɑː/