Search Result for "sniffer": 
Wordnet 3.0

NOUN (1)

1. a person who sniffs;

WordNet (r) 3.0 (2006):

sniffer n 1: a person who sniffs
The Free On-line Dictionary of Computing (30 December 2018):

packet sniffer sniffer A network monitoring tool that captures data packets and decodes them using built-in knowledge of common protocols. Sniffers are used to debug and monitor networking problems. (1995-03-28)