Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
foully is an adverb meaning "in an unfair and insulting manner". It carries 2 recorded senses.
in an unfair and insulting manner
“this internationally known writer was foully condemned by the Muslim fundamentalists”
in a wicked and shameful manner
“two policemen were foully murdered”
Definitions, synonyms and semantic relations for foully come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.