noun

• (humorous) A dense head of hair.
  "He ran a comb through his mop and hurried out the door."
• (British, dialect, West Midlands) An annual fair where servants were historically hired.
  "I means to goo to th' mop, 'er sez, fur I waants a chahinge.[…]'T wuz to w:Muckley mop 'er went."
• (British, obsolete) A tassel worn in a buttonhole to indicate ones occupation in such a fair.
  "Mop Fairs: Today's annual events are the modern version of the old hiring fairs, where people attended seeking employment or to change it. They are named after the practice of hopefully skilled employees carrying tassels, known as mops, in their buttonholes indicating their occupation. Those who had no trade carried a mop head. At the end of the following week, they could change employers or employees, at what was called the Runaway Mop."
• (African-American Vernacular, MLE, slang) A firearm particularly if it has a large magazine (compare broom, but still can be related to MP)
  "Mainstream in this ting but I'm fully on opps Got shot with a mop but that boy never dropped"

verb

• (transitive) To rub, scrub, clean or wipe with a mop, or as if with a mop.
  "to mop (or scrub) a floor"
• (US, slang) To shoplift.
  "By “mopping” (stealing) the clothes and accessories necessary to effect their look, or by buying breasts, reconstructed noses, lifted chins, and female genitals, the children turn traditional ideas of labor around: […]"

noun

• (British, dialect, obsolete) The young of any animal.
• (British, dialect, obsolete) A young girl; a moppet.

verb

• (intransitive) To make a wry expression with the mouth.
  "Flibbertigibbet,[is scared of]moping and mowing, who since possesses chambermaids and waiting-women"