A bound katakana suffix corresponding to English noun-forming -ness. It is mainly seen inside loanwords or when discussing English-derived forms, rather than freely attached to ordinary Japanese adjectives.
The final ネス in フィットネス corresponds to English -ness.
カタカナ語では、ハッピーにネスが付いて「ハッピネス」のような形になることがある。
In katakana words, ネス can be added to forms like ハッピー, producing forms such as ハッピネス.
loudness
ugliness
madness; insanity
readiness
This katakana suffix represents the English noun-forming ending -ness in Japanese loanword spelling; no separate etymological note is specified.