WordWeb Online

1. Do random, unplanned work, activities or spend time idly
   "The old lady is usually mucking about in her little house";
   - putter [N. Amer], mess around, potter [Brit], tinker, monkey around [informal], muck around [Brit, informal]
    
2. Behave in a foolish, fun way; indulge in horseplay
   - horse around, arse around [Brit, Cdn, informal], fool around, fool, muck around [Brit, informal], arse about [Brit, Cdn, informal], kid around [informal], screw around [informal]

Derived forms: mucked about, mucking about, mucks about

Type of: jest, joke, play, work