Handle

[Sarah]

To use the hands.They have hands, but they handle not. Ps. cxv. 7.

[Sarah]

A half gallon of liquor. It gets its name from the little handle that's always on half gallons.

[Sarah]

A 1.75 litre bottle of alcohol, which is approximately half a gallon. Usually bottles this size have a handle for easy carrying, hence the name.

[Sarah]

One's online name. Often, a hacker will use a handle, and will be referred to by this handle by all his associates, to help lessen the chances of his getting caught. Also, often a privacy measure.

[Mark Zuckerberg]

To take care of something; to get something done

[Monty]

In the online world, a handle is another word for a username. It can refer to the name you use in chat rooms, web forums, and social media services like Twitter.
The term handle dates back to the 1970s and comes from Citizens Band radio (CB radio), a short distance radio communications medium. CB radio users would identify themselves by unique nicknames, which became known as handles. When online chat became popular in the 1990s, the term handle transferred to the Internet and became a common way for users to identify themselves online.
While handle and username are often used synonymously, they do not always mean the same thing. For example, when you choose a username for a secure website like a bank or investment site, it is not necessarily your handle. This is because the username is intended to be private and used in combination with a password to create your login. Handles, on the other hand, are public usernames that can be used to identify people online.
The most popular web service to use handles is Twitter. In fact, Twitter usernames are often called Twitter handles. You can reference other users in a tweet using Mentions or the @reply feature. To mention another Twitter user in your post, simply type an at symbol (@) immediately before the users handle. A link to the users profile will show up in the published tweet and the user will be notified that you have mentioned or replied to him or her.