1/ noun. happiness, 幸福，幸福 [u]
2/ noun. the fact that words or remarks are suitable and express what was intended. 文字或語言的）貼切，恰當，得體 [u]
3/ a word or remark that is suitable or right and expresses well the intended thought or feeling [C usually plural]
Source: Cambridge Dictionary
https://dictionary.cambridge.org/dictionary/english-chinese-traditional/felicity