What is the meaning of penetration?

noun

• An attack that penetrates into enemy territory.
  • synonyms: incursion
• Clear or deep perception of a situation.
  • synonyms: insight
• The act of entering into or through something.
  • usage: "the penetration of upper management by women"
• The ability to make way into or through something.
  • usage: "the greater penetration of the new projectiles will result in greater injuries"
• The depth to which something penetrates (especially the depth reached by a projectile that hits a target. )
• The act (by a man) of inserting his penis into the vagina of a woman. .