from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Software that secretly gathers information about a person or organization.
- n. Any malicious software that is designed to take partial or full control of a computer's operation without the knowledge of its user.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. programs that surreptitiously monitor and report the actions of a computer user.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. computer software that obtains information from a user's computer without the user's knowledge or consent
From spy + -ware (Wiktionary)