Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
generousness is a noun meaning "the trait of being willing to give your money or time". It carries one recorded sense.
the trait of being willing to give your money or time
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for generousness come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.