Entry 1 sense Webster, 1913 Irrefragability /(ĭr*rĕf"rȧ*gȧ*b'l)/ · Ir·ref·ra·ga·bil·i·ty · IPA 01 n. The quality or state of being irrefragable; incapability of being refuted. 1. The quality or state of being irrefragable; incapability of being refuted.