1. cleaning out dirt, manure, or debris from a stable, barn, or similar area
Usage: present participle of ‘muck’
2. moving or working with mud, dirt, or messy materials
Usage: informal
3. interfering with or tampering with something
Usage: informal; usually with ‘about’ or ‘around’

Examples

• The farmer spent the morning mucking out the horse stalls.
• She was mucking around in the garden, planting new flowers.
• Stop mucking about with that machine or you’ll break it.
• The stable hands were mucking the barn before the horses returned.
• He’s been mucking around with the computer settings all day.
• After mucking out the chicken coop, she washed her hands thoroughly.