Even the lowliest will sometimes come to the fore, as in They may not listen to me now, but just wait, every dog has its day. This proverbial saying alludes to the lowly status dogs once held. [Mid-1500s] Also see had its day.

The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Company. All rights reserved.