Entry 1 sense Webster, 1913 Irrefrangible · Ir·re·fran·gi·ble · IPA /ˌɪɹɪˈfɹænd͡ʒəbəl/ 01 a. Not refrangible; that can not be refracted in passing from one medium to another. 1. Not refrangible; that can not be refracted in passing from one medium to another.