What Does Ness Mean As A Suffix?

Https://www.msu.edu/~defores1/gre/sufx/gre_suffx.htm
This site contains the list of suffix meanings.
the suffix "ness" means "state of"
carelessness means a state of being careless
uselessness means a state of being useless

The suffix -ness is a native English suffix which is attached to adjectives and participles. It is used to form abstract nouns. These abstract nouns express quality or state. The suffix -ness is added to words such as good to get goodness, great (greatness), dark (darkness), kind (kindness), obliging (obligingness), prepared (preparedness), bright (brightness) and busy (business).

The suffix -ness is derived from the Middle English suffixes -nes or -nis. It is, in turn, derived from an Old English word, which is similar to the Old High German suffix -nissa and the Gothic -(n)assus. The suffix -ness is added at the end of an adjective to indicate the state, condition, quality or degree or something.

The suffix -(n)assus has been derived from the combination of two suffixes, namely the original suffix -assus and the suffix -n, which means by the false division of words with adjective and participle stems ending in the suffix -n. It is, in turn, derived from the Old English word efnes, which was later spelt as efen -nys. Both these words, namely efnes and efen -nys, mean evenness.

A native English suffix attached to adjectives and participles, forming abstract nouns denoting quality and state (and often, by extension, something exemplifying a quality or state): Darkness; goodness; kindness; obliviousness; preparedness.