Entry 1 sense Webster, 1913 Hystricomorphous /(hĭs`trĭ*kō̇*môr"fŭs)/ · Hys·tri·co·mor·phous · IPA 01 a. Like, or allied to, the porcupines; -- said of a group (Hystricomorpha) of rodents. 1. Like, or allied to, the porcupines; -- said of a group (Hystricomorpha) of rodents.(Zool.)