IPA: /ˈplɛntɪəsnəs/
KK: /ˈplɛntɪəsnəs/
A large amount of something; a state of having plenty or abundance.
The garden was filled with the plenteousness of fruits and vegetables during the harvest season.
Plenteousness → It is formed from "plenteous" (from Old French *plenteus*, meaning abundant) and the suffix "-ness" (meaning the state or quality of). The word "plenteousness" refers to the state of being abundant or plentiful.
Think of 'plenteous' meaning abundant, and remember that '-ness' indicates a state or quality. So, plenteousness is the quality of being abundant.