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Synonyms

sniffer

American  
[snif-er] / ˈsnɪf ər /

noun

  1. a person or thing that sniffs.

  2. a device or mechanism for detecting something.

sniffer British  
/ ˈsnɪfə /

noun

  1. a device for detecting hidden substances such as drugs or explosives, esp by their odour

  2. a computer program or device used to monitor, detect, and capture data on a network

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of sniffer

First recorded in 1860–65; sniff + -er 1

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Footage from the campsite on Mount Maunganui shows rescuers and sniffer dogs combing through crushed caravans and flattened tents.

From BBC • Jan. 22, 2026

Deputy police commissioner Sahibzada Yousaf told local media that sniffer dogs and advanced technology were used to ensure everyone was rescued from the rubble.

From BBC • Jan. 11, 2026

One of the boys allegedly walked past the offices of Europol, Eurojust and the Canadian embassy in The Hague carrying a "wi-fi sniffer" - a device designed to identify and intercept wi-fi networks.

From BBC • Sep. 26, 2025

But it is this strong smell, as well as the smell associated with their insect poo - frass - that makes them ideal to be found by sniffer dogs.

From BBC • Aug. 30, 2025

“So, you’re a book sniffer, is that what you’re telling me?”

From "I Am Not Your Perfect Mexican Daughter" by Erika L. Sánchez

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.