Definition of declination in English:



  • 1Astronomy
    The angular distance of a point north or south of the celestial equator.

    ‘the declination of Arcturus is 19 degrees north’
    • ‘Consistently, equinoctial markers and alignments were made to an declination well over half a degree to the north.’
    • ‘Also every month, the Moon will reach its minimum declination at 18 north or south.’
    • ‘It's easy enough to gauge an asteroid's longitude and latitude (ascension and declination in astro-speak), but figuring out its current celestial position is tricky.’
    • ‘To calculate the distance we need to know the declination of the sun on a given day.’
    • ‘He also determined the latitude and longitude of many stars, and measured the greatest declination of the planet Mercury.’
    1. 1.1The angular deviation of a compass needle from true north (because the magnetic north pole and the geographic north pole do not coincide).
      • ‘On the North Rim the difference between map and compass is 15 east, a distinction known as magnetic declination.’
      • ‘Proposals were being made to solve the longitude problem and in 1673 one based on magnetic declination was proposed by a certain Henry Bond.’
      • ‘He also studied magnetic declination and was the first to observe the secular variation.’
      • ‘The compass needle and a knowledge of magnetic declination, the angle between the magnetic north and geographic north, were developments from this knowledge; they were described by Shen Kua in 1088.’
      • ‘Gellibrand's most famous scientific discovery was the change over the years in magnetic declination.’
      turning aside, turning away, turning, diversion, drawing away
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  • 2Linguistics

    another term for downdrift
  • 3US Formal refusal.

    [as modifier] ‘the mandatory vaccine declination form’
    • ‘The actual declination letter disappeared from the file.’
    refusal, withholding, withdrawal
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Late Middle English: from Latin declinatio(n-), from the verb declinare (see decline).