A word that hasn’t come up yet on OffQc…
Your dictionary will tell you that mud is la boue, but you’ll also hear la bouette in Québec.
If someone had muddy boots on, you could describe them as bottes pleines de bouette.
You can say to play in the mud as jouer dans la bouette.
Remember, the words dans la can contract to dans’ in informal language, so jouer dans la bouette can sound like jouer dans’ bouette.