Word Study
interdenominational
CIDE DICTIONARY
interdenominational, a.
Occurring between or among, or common to, different denominations; as, interdenominational fellowship or belief. [Webster 1913 Suppl.]
OXFORD DICTIONARY
interdenominational, adj. concerning more than one (religious) denomination.
Derivative
interdenominationally adv.
For further exploring for "interdenominational" in Webster Dictionary Online