The British spelling of equalization; the act or process of making things equal or bringing them to the same level.
From equalise (British spelling of equalize) + -ation (the act of). Equalise comes from equal + -ise (British suffix for creating verbs). The -ation suffix is from Latin, forming nouns from verbs.
The British spelling 'equalisation' with its -s- instead of -z- is actually historically older—American English adopted the -z- under Greek influence, but British English kept the Romance -s-, making spelling differences reveal language evolution.
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