Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
trustingness is a noun meaning "the trait of believing in the honesty and reliability of others". It carries one recorded sense.
the trait of believing in the honesty and reliability of others
“the experience destroyed his trust and personal dignity”
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 trustingness come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.