The quality or state of being big; size, magnitude, or importance.
From 'big' plus the noun-forming suffix '-ness,' a common English pattern for creating abstract nouns describing qualities.
The suffix '-ness' is one of English's most productive tools—we can add it to almost any adjective and create a noun. 'Bigness' seems simple, but it's profound: it's not 'size' but the essential quality of being large.
Complete word intelligence in one call. Free tier — 50 lookups/day.