To make something etherial or heavenly; to give something a light, airy, or spiritual quality.
From etherial plus -ise (British English verb suffix). The British spelling variant of etherealize.
Both 'etherealize' and 'etherialise' exist as competing spelling variants across different regions and time periods — English never completely standardized which root adjective (ethereal vs. etherial) people would use as their base.
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