con ‧ sti ‧ tu ‧ tion ‧ al ‧ i ‧ ty /ˌkɒnstətjuːʃəˈnæləti, ˌkɒnstɪtjuːʃəˈnæləti $ ˌkɑːnstətuː-/ BrE AmE noun [uncountable]
the quality of being acceptable according to a constitution:
A decision on the proposal’s constitutionality still has to be made.