/ ˌpenɪˈtreɪʃn; NAmE / noun [ U ]
1.
the act or process of making a way into or through sth :
The floor is sealed to prevent water penetration.
the company's successful penetration of overseas markets
2.
the act of a man putting his penis into his partner's vagina or anus
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WORD ORIGIN
late Middle English : from Latin penetratio(n-) , from the verb penetrare place within or enter.