The suffix 'ness' can be best defined as?

The suffix 'ness' is used to form nouns that express a state, condition, or quality of something. When added to an adjective, it transforms that word to reflect the quality associated with the original word. For example, 'happiness' denotes the quality of being happy, while 'darkness' reflects the quality associated with being dark. Therefore, defining the suffix 'ness' as "quality of" aligns perfectly with its function in the English language.

This understanding clarifies the usage of the suffix in varying contexts and highlights how it contributes to the meaning of words by reinforcing their inherent characteristics or states.