From Longman Dictionary of Contemporary Englishinterdepartmentalin‧ter‧de‧part‧men‧tal /ˌɪntəˌdiːpɑːtˈmentl $ ˌɪntərdɪˌpɑːrtˈmentl/ adjective [usually before noun] BETWEENbetween or involving different departments of a company, government etc intense interdepartmental rivalry
Examples from the Corpus
interdepartmental• The college's interdepartmental mail system is extremely efficient. 