Entry 2 senses Webster, 1913 Perforation /pẽrfˌ-ẽr-āsh'-ən/ · Per·fo·ra·tion · IPA /ˌpɚfəˈreɪʃən/ 01 n. The act of perforating, or of boring or piercing through. 1. The act of perforating, or of boring or piercing through. 2. A hole made by boring or piercing; an aperture.