Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
trustfully is an adverb meaning "with trust; in a trusting manner". It carries 2 recorded senses.
with trust; in a trusting manner
“she looked at her father trustingly”
in a trustful manner
“his mouth grinned trustfully”
Definitions, synonyms and semantic relations for trustfully come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.