As it is now the case that; seeing as; considering. Now that everyone is here, let's begin the meeting. I was about to head home, but now that we've started on the next illustration, we might as well finish it before the weekend.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
Seeing that, since, as in Now that you're here, you might as well stay for dinner. This usage was first recorded in 1530. For a synonym, see as long as.
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.