• equalise (non-Oxford British spelling)
• æqualize (obsolete)

From equal +‎ -ize.

• (UK) IPA^(key): /ˈiːkwəlaɪz/

  • Audio (Southern England):

    (file)

• (US) IPA^(key): /ˈikwəˌlaɪz/

equalize (third-person singular simple present equalizes, present participle equalizing, simple past and past participle equalized)

1. (transitive) To make equal; to cause to correspond in amount or degree.

   to equalize accounts, burdens, or taxes

   • 1815, William Wordsworth, Epitaph 3:

     One poor moment can suffice / To equalize the lofty and the low.

   • 1828, Richard Whately, Elements of Rhetoric:

     No system of instruction will completely equalize natural powers.

2. (obsolete, transitive) To be equal to; to equal, to rival. [16th–19th c.]
   • 1590, Edmund Spenser, “Book III, Canto IX”, in The Faerie Queene.[…], London: […] [John Wolfe] for William Ponsonbie, →OCLC:

     But a third kingdom yet is to arise / Out of the Trojans scattered ofspring, / That in all glory and great enterprise, / Both first and second Troy shall dare to equalise.

   • 1649, J[ohn] Milton, ΕΙΚΟΝΟΚΛΆΣΤΗΣ [Eikonoklástēs][…], London: […] Matthew Simmons,[…], →OCLC:

     polling the reformed churches whether they equalize in number those of his three kingdoms

3. (intransitive, sports) To make the scoreline equal by scoring points. [from 20th c.]
4. (underwater diving) To clear the ears to balance the pressure in the middle ear with the outside pressure by letting air enter along the Eustachian tubes.
5. (category theory, of a morphism) to precompose with each of a parallel pair of morphisms so as to yield the same composite morphism.
6. (signal processing) To adjust the balance between frequency components within an electronic signal.
   • 1987, The Shock and Vibration Bulletin - Volume 57, Parts 1-4, page 35:

     The technique for frequency slewing of a transient is different from that for vibration testing in that it is necessary to equalize at low level as the clock frequency is slewed in relatively small increments from the nominal to the desired frequency.