Source : WordNet®

imperativeness
     n 1: the state of urgently demanding notice or attention; "the
          press of business matters" [syn: {insistence}, {insistency},
           {press}, {pressure}]
     2: urgently demanding attention; "the insistence of their
        hunger"; "he pressed his demand with considerable
        instancy" [syn: {insistence}, {insistency}, {instancy}]