From Wiktionary, the free dictionary

From normal +‎ -isation or normalise +‎ -ation.

normalisation (countable and uncountable, plural normalisations)

1. Non-Oxford British English standard spelling of normalization.

   • 2010 June 30, Mark Weisbrot, “One year on, Honduras rift persists”, in The Guardian‎^[1]:

     Two days later Clinton announced that the US was restoring all assistance to Honduras despite a letter sent to her the day before by Democratic members of Congress asking her to "send a strong unambiguous message that the human rights situation in Honduras will be a critical component of upcoming decisions regarding the further normalisations of relations, as well as the resumption of financial assistance".

   • 2022 February 28, Daniel Boffey, “Ukraine conflict leads EU to rid itself of Russian sacred cows”, in The Guardian‎^[2], Guardian Media Group, retrieved 28 February 2022:

     Since Ostpolitik, the normalisation of relations between then West Germany and the east, policy has been predicated upon Russia being a status quo power, not an imperialist one.

From normaliser +‎ -ation.

• IPA^(key): /nɔʁ.ma.li.za.sjɔ̃/

normalisation f (plural normalisations)

1. normalization

• “normalisation”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012