The quality or state of being customizable; the degree to which something can be modified or personalized.
From 'customable' plus the suffix '-ness' (quality or state), a standard English formation for creating abstract nouns. This word is extremely rare, as 'customizability' is the modern preferred form.
This is a genuinely obscure word that shows how English speakers naturally gravitate toward certain suffixes—while '-ness' was added to adjectives in older English, modern tech language prefers '-ability' and '-ization' endings, making 'customableness' sound quaintly outdated.
Complete word intelligence in one call. Free tier — 50 lookups/day.