What does impure mean?
“Impure” describes something that is not pure, especially when it contains foreign, harmful, or undesirable substances. The word commonly refers to contaminated water, air, food, or chemicals, where it suggests a departure from a clean or uncontaminated state. It can also describe conduct, thoughts, motives, or religious practices as morally, spiritually, or sexually corrupt. In these figurative uses, “impure” often suggests contamination of something that should remain morally or spiritually clean. Because of these associations, it can sound more formal and severe than “dirty,” especially when used in religious or moral language. The word is related to the Latin “impurus,” meaning “not pure,” and belongs to a family including “purity” and “purify.”
adjectiveNot pure; containing foreign, harmful, or undesirable substances. In moral, religious, or sexual contexts, it can mean corrupt, impure, or contrary to accepted standards.
- Not pure; containing foreign, harmful, or otherwise undesirable substances.
- Morally, religiously, or sexually corrupt or impure.
"The factory was accused of discharging impure water into the river."
"The laboratory tested the sample and found that the water was impure."
"She forgave him for acting from impure motives."
In “impure,” the “im-” is a tiny prefix with a long reach: what begins as physical contamination can also describe moral or spiritual corruption.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does impure come from?
“Impure” comes from Latin “impurus,” formed from the negative prefix “in-” and “purus,” meaning “pure.” The word entered English with the meaning “not pure” and developed figurative uses concerning moral and religious cleanliness. The same Latin root underlies related English words such as “pure,” “purity,” and “purify.”
Related word forms
How impure is actually used
In physical contexts, “impure” is more formal or technical than “dirty.” In moral, religious, or sexual contexts, it can sound traditional, severe, or judgmental.