Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
interdepartmental is an adjective and adverb meaning "between or among departments". It carries 2 recorded senses.
between departments
“this memo was circulated interdepartmentally”
Definitions, synonyms and semantic relations for interdepartmental come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.