Entry 1 sense Webster, 1913 Circumferential · Cir·cum·fer·en·tial · IPA /sɝ.kəm.f(ə)ˈɹɛn.ʃəl/ 01 a. Pertaining to the circumference; encompassing; encircling; circuitous. 1. Pertaining to the circumference; encompassing; encircling; circuitous.