- a one-piece garment combining a top with trousers, worn by adults as leisurewear
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Examples from the Web for onesie
Make a batch of these rum balls, climb into a onesie, and let your favorite movie do the rest.Carla Hall’s Christmas Day Treat: Rum Balls
December 25, 2014
At CES this year, Intel showed off a onesie equipped with a chip that monitors vitals and movement.Are We Turning Our Babies Into Real Life Tamagotchis?
August 7, 2014
He wore Spider-Man onesie pajamas to bed when he was a little boy.Dane DeHaan’s Green Goblin Is the Best Thing About ‘The Amazing Spider-Man 2’
May 2, 2014
The site called the onesie "ridiculous" and encouraged readers not to purchase it.
Robbi Potter, vice president and designer at Lyn Dorf, doesn't even take the onesie's message seriously.