English Reference
noun

penetration

n.
US /ˌpɛnəˈtɹeɪʃən/ UK /pˌɛnɪtɹˈeɪʃən/ pen·e·tra·tion UK spelling penetrations

  1. 01 B2 Upper Intermediate

    the act of moving into or through something, like a needle going into skin or a bullet hitting a target.

    the act or process of piercing or entering a physical body or substance.

    Simple

    The thick walls of the old castle prevented the penetration of the radio signal.

    In context

    The armour was specifically designed to resist the penetration of high-velocity projectiles during close-quarters combat.

    Usage

    often used with the preposition 'of' or 'into'

    entrypiercingperforation
  2. 02 C1 Advanced AcademicTechnical

    the percentage of people in a group who buy a certain product or use a service.

    the extent to which a product or service is recognised or bought by a particular target market.

    Simple

    The company is happy with its market penetration in Europe this year.

    In context

    Despite aggressive advertising campaigns, the brand struggled to achieve significant market penetration in rural territories dominated by local competitors.

    Usage

    frequently appears in the compound 'market penetration'

  3. 03 C1 Advanced FormalLiterary

    the ability to understand complicated ideas or see the truth in a situation.

    the capacity for acute mental discernment or the act of perceiving the inner nature of a situation.

    Simple

    Her analysis of the problem showed great intellectual penetration.

    In context

    The philosopher was celebrated for his remarkable penetration, often identifying logical fallacies that his contemporaries had overlooked for decades.

    shallownessignorance
  4. 04 C1 Advanced TechnicalFormal Medicine

    the act of one body part or object entering another during sex.

    the insertion of the penis or an object into a body orifice during sexual activity.

    Simple

    The doctor explained that the injury occurred during penetration.

    In context

    Legal definitions of the act often hinge on the specific degree of penetration recorded in the forensic report.

    Usage

    used in medical, legal, or formal biological contexts

The researchers produced a base material with a hardness above 1400 HV (a unit representing resistance to penetration), without causing defects or decomposition.

ScienceDaily· 4 Aug 2026

From Middle English penetracioun, from Old French penetracïon, and its source, Latin penetrātiō, from the participle stem of penetrō (“pierce”, verb). Morphologically penetrate + -ion.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin penetrātiō
Level C1 · Advanced
Frequency Frequent
Updated