to bring up to date; make conform to or aware of the most recent facts, methods, ideas, etc.

There are two ways to update virus definitions: -- LiveUpdate -- The Intelligent Updater This document helps you decide which you should use and when.

To use the .XDB file to update your virus definitions, read the "Copying an .xdb file" section in the document that is for your version of Symantec AntiVirus:

Spyware and Adware can slow down your computer and they pose a security threat. Learn how to detect and delete the spyware and adware on your computer.

update - 4 dictionary results ... 1. news that updates your information : verb: 1. modernize or bring up to date;