Impenetrable: meaning, definitions and examples

Use this word for something that cannot be physically or metaphorically entered or understood.

• The dense forest was impenetrable
• His motives were impenetrable

Use this word when something is so deep or complex that it cannot be fully understood or measured.

• The universe is unfathomable in its vastness

Use this word when something is mysterious or difficult to interpret, usually referring to a person's expression or intentions.

• She had an inscrutable smile that made it hard to know what she was thinking

Use this word when something cannot be understood or is beyond understanding, often in a negative or frustrating sense.

• The professor's lecture was completely incomprehensible

Used to describe something that cannot be passed through, understood, or seen through. Often applied to dense materials, complex ideas, or thick forests.

• The walls of the fortress were impenetrable.
• His mind seemed impenetrable to reason.
• The jungle was so thick, it was impenetrable.

Describes something or someone that does not give in under pressure, whether physical or mental. Often used to describe firm determination or a hard, solid surface.

• Her unyielding spirit kept her going through tough times.
• The unyielding door would not budge even an inch.

Refers to a route or path that cannot be traveled through, especially because of obstacles or barriers. Typically used in the context of roads, trails, or passages.

• The road became impassable after the heavy snowfall.
• The mountain trail was deemed impassable due to a landslide.

Describes a material that does not allow liquids or gases to pass through. Commonly used in scientific, environmental, or technical contexts.

• The container is made of an impermeable material to prevent leaks.
• An impermeable membrane was used in the experiment.