To send some one an e-mail using Gmail.
"I will gmail my colleague to let her know about the meeting change."
In plain English: To gmail someone means to send them an email using your Gmail account.
"He decided to gmail his friend instead of calling him on the phone."
A web-based e-mail system provided by Google (trademarked Gmail).
"I checked my inbox on Gmail to see if the invitation had arrived."
Gmail is a blend of the words Google and mail that was first used to describe the company's free web-based email service. The name directly combines the brand with the function of sending messages.