Entry 1 sense Webster, 1913 Incommensurability · In·com·men·su·ra·bil·i·ty · IPA /ˌɪŋkəˌmɛnʃʊɹəˈbɪlɪti/ 01 n. The quality or state of being incommensurable. 1. The quality or state of being incommensurable.