D defs.my
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. 1.
    The act of perforating, or of boring or piercing through.
  2. 2.
    A hole made by boring or piercing; an aperture.