Perforation

n. puncturing, making holes

A perforation is a hole made by puncturing a surface. However, the term frequently refers to the practice of creating a long series of holes so that paper can be torn more easily.  Postage stamps are one common application of this, where small round holes are cut in lines to create individual pieces (see postage stamp separation). Since the creation of perforation devices in the 1840s and 1850s, it has seen use in several areas. It is common for notebooks and legal pads to have perforations making it easier to tear out individual pages. Perforations on stamps are rather large, on the order of a millimeter, in comparison with other perforated materials often have smaller holes. Film stock is perforated to allow it to be moved precise distances at a time continuously.  Screwcaps on glass or plastic bottles are sealed with a ring at the bottom of the cap attached by perforation. Twisting the cap has the effect of rupturing the perforation and indicating that the original seal has been broken.
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Per·fo·ra·tion n. 1. The act of perforating or the state of being perforated. 2. An abnormal opening in a hollow organ or viscus, as one made by [more]Perforation - Community and Resources

Noun
1. a line of small holes for tearing at a particular place
(hypernym) hole
(derivation) punch, perforate
2. a hole made in something; "a perforation of the eardrum"
(hypernym) hole
(derivation) penetrate, perforate
3. the act of punching a hole (especially a row of holes as for ease of separation)
(hypernym) puncture
(derivation) punch, perforate

n. perforation, puncturing, making holes