from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Malicious computer software that interferes with normal computer functions or sends personal data about the user to unauthorized parties over the Internet.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Software which has been designed to operate in a malicious, undesirable manner.
mal(icious) + -ware.(American Heritage® Dictionary of the English Language, Fourth Edition)
Blend of malicious and software (Wiktionary)