The quality or state of being fussy; the tendency to worry excessively about small details or to complain unnecessarily.
From 'fussy' (adjective) plus the suffix '-ness', which creates an abstract noun denoting a quality or state.
The '-ness' suffix is one of the oldest in English, going back over a thousand years—it's so fundamental that it feels almost invisible to us.
Complete word intelligence in one call. Free tier — 50 lookups/day.