What does sniff mean?
To sniff is to draw air through the nose, usually with a short, audible movement, in order to smell something or investigate it. In everyday use, the word describes checking a scent, such as sniffing the air to detect smoke or food. It can also mean making a conspicuous nasal sound, often as a sign of hesitation, discomfort, or disdain. Figuratively, “to sniff out” means to discover or expose something through careful observation, intuition, or investigation. As a noun, “a sniff” refers to the act or sound of smelling through the nose, and expressions such as “take a sniff” and “get a sniff of” are established in both British and American English. The word is especially useful because it covers both a literal physical action and the common idea of searching for traces of information, opportunity, or wrongdoing.
To smell the air or an object by drawing it through the nose, often with a short, audible breath; to investigate or detect something; or to show contempt by sniffing at it.
"He sniffed the letter suspiciously and handed it back."
The phrase “sniff out” is informal and means to detect or discover something.
An act or instance of drawing air through the nose to smell something, or the short nasal sound produced in doing so.
"She took a long sniff of the perfume."
The plural is used for individual acts or sounds of sniffing and is uncommon compared with the plural of the related sense of a detection or opportunity.
"The dog gave several short sniffs before barking."
A single sniff can mean smelling, searching, or quietly judging something—and in English, even that little nose sound can carry a world of suspicion.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does sniff come from?
The word comes through Middle English from Old English snifan, meaning to draw air through the nose or smell. Its development reflects the long-standing Germanic use of nasal sound and smell, and it is related to forms such as German schnüffeln and to related words including snuffle and snivel. The modern figurative senses developed from the basic idea of searching with the senses.
Related word forms
How sniff is actually used
The verb is neutral when used for smelling. In its figurative senses, such as “sniff out,” it can suggest detecting something through intuition or investigation. “Sniff at” has a dismissive or contemptuous connotation. As a noun, “a sniff” is common in both formal and informal contexts.
Easily confused with sniff
To sniffle is to breathe noisily through the nose, often because of a cold or crying, whereas to sniff is primarily to smell something or investigate it briefly.