n.1. The act or process of piercing or penetrating something, especially:
a. The act of entering a country or organization so as to establish influence or gain information.
b. An attack that penetrates enemy territory or a military front.
c. Insertion of the penis into the vagina or anus.
2. The power or ability to penetrate.
3. The depth reached by a projectile after hitting its target.
4. a. The degree to which a commodity, for example, is sold or recognized in a particular market.
b. The extent of influence that one culture or nation has on another.
5. The capacity or action of understanding; insight.