A child who plays with or in water or other liquids, potentially creating a mess.
The term was in use in the LaBrecque family in Elmira, New York in the late 1930s, but as such may have earlier French-Canadian origins (Beaumont, Quebec).
* A five-year-old who mashes up a bowl of ice cream into a soup using the back of a spoon.
* A four-year-old who drags a chair over to the kitchen sink and pours tap water back and forth between pots, bowls, or glasses.
* A three-year-old splashing in a bath, or conveying bathwater between shampoo bottles or rinsing basins, long past the point of cleanliness.
All are examples of a muxie duxer (the child) engaged in muxie duxing (the activity).
Using the term to describe combining different colors of Play-Doh or modeling clay into a brown lump is a colloquial misuse of the term, as those materials are not technically liquids.
Swimming activities are not as a rule considered muxie duxing as the facilities tend to be designed to contain any mess created.
The term may be applied pejoratively to an unskilled or especially slow bartender.