Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
positiveness is a noun meaning "the character of the positive electric pole". It carries 5 recorded senses.
the character of the positive electric pole
a quality or state characterized by certainty or acceptance or affirmation and dogmatic assertiveness
the quality of being encouraging or promising of a successful outcome
an amount greater than zero
the quality of being undeniable and not worth arguing about
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 positiveness come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.