impenetrability
impenetrability — noun
1. a state in which something is so thick, solid, or well-defended that nothing can
a state in which something is so thick, solid, or well-defended that nothing can get through or look through it
The ancient fortress walls had an impenetrability that no army could overcome.
noun + that-clause to describe the quality's effect
Hannah stared at the dense fog, surprised by its impenetrability to the morning light.
pattern: impenetrability + to [something trying to pass]
The impenetrability of the jungle made the search for the lost hikers extremely difficult.
Minho tested the impenetrability of the new security glass by firing at it.
- porosity
the quality of having small holes that let liquids or gases pass through
- permeability
the degree to which a substance allows liquids or gases to pass through it
文法句型
the impenetrability of [something]
用法筆記
Frequently followed by 'of' + a physical object (wall, forest, shield) or 'to' + what tries to pass (light, bullets, people). Common in military, architectural, and environmental contexts.
2. the extent to which a piece of writing, a set of rules, or an idea is so hard to
the extent to which a piece of writing, a set of rules, or an idea is so hard to grasp that no amount of effort makes it clearer
Layla sighed at the impenetrability of the philosophy text her teacher had assigned.
pattern: impenetrability + of [complex written material]
The impenetrability of the tax forms frustrated Nicholas, so he hired an expert.
impenetrability of [official document] causing frustration
Romi enjoyed the poem but found its impenetrability made it hard to discuss with others.
The impenetrability of the ancient code meant only a few experts could read it.
- obscurity
suggests something is not well-known rather than actively hard to understand
- incomprehensibility
a more direct synonym, though slightly more technical in tone
- opacity
metaphorically describes something as 'not transparent' to understanding
文法句型
the impenetrability of [complex subject]
用法筆記
Typically used with 'of' + an abstract object such as a text, theory, explanation, or set of instructions. Often carries a tone of frustration or respectful difficulty. More common in academic writing than everyday speech.