What does penetrable mean?
Penetrable means able to be pierced, entered, or passed through. In its literal sense, it describes a material, barrier, or defense that does not completely prevent access. The word can also be used figuratively for ideas, arguments, or emotional states that can be understood, challenged, or affected. Its implication is usually that protection or resistance has a flaw, although the degree to which something is penetrable can vary. This distinguishes it from impermeable, which focuses more on preventing substances from passing through, and from impenetrable, its direct negative. Penetrable is formal and relatively uncommon in everyday speech, but it remains useful in discussion of defense, biology, security, and critical thought. It is also related to penetrate and penetration, words that emphasize an act of entry rather than a capacity for entry.
adjectiveAble to be pierced, entered, or passed through. Figuratively, able to be understood, challenged, or affected.
- Able to be pierced, entered, or passed through; not secure against penetration.
"The shield was penetrable, but its makers had overlooked the seam along the side."
"The shield was penetrable, but its makers had overlooked the seam along the side."
"The theory was penetrable: one carefully chosen counterexample would expose its weakness."
Penetrable is a wall that can be pierced—and an idea that can be got into.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does penetrable come from?
Penetrable was borrowed into English from Latin penetrābilis, meaning “capable of being pierced or entered,” which was formed from penetrāre, “to pierce or penetrate,” using the adjectival suffix -ābilis. In English, penetrable developed alongside related forms such as penetrate, penetration, and penetrative. Its negative counterpart, impenetrable, was formed by adding the prefix im- to the same inherited base.
Related word forms
How penetrable is actually used
Formal and relatively uncommon in contemporary English. The negative form impenetrable is much more frequent, especially when describing defenses, mysteries, or personalities.
Easily confused with penetrable
Penetrable means capable of being pierced or entered, whereas permeable more often means allowing a substance or material to pass through.
Impenetrable is the negative form of penetrable and means impossible to pierce, enter, or understand.