A one piece snow suit. Worn back in the day when skiing was young. Now commonly worn by thy Gaper. Comes in Solid or Multiple bright colors. Do NOT wear in Colorado or you shall get mugged.
by A Local Coloradian May 2, 2009

by ElizabethDrake June 3, 2018

by Scrubby May 6, 2008

a single cigarette sold over the counter by a retail establishment, instead of a pack of 20. useful in New York if you don't have the $8 for a pack. also useful for the quitting smoker who just needs one nicotine hit to take the edge off. onesie's are illegal in some states - eg Illinois 2009
"he sold me a onesie with a cup of coffee"
by mak108 August 22, 2009

by Dirk420 September 7, 2006

Emma's a Onesie!
by Lateofthepier October 20, 2009

by cousinjack49 April 23, 2014
