noun

• (figurative, usually derogatory) An establishment that handles a certain type of situation or procedure routinely, or produces large quantities of an item without much regard to quality. (The notion of churning out massive amounts indiscriminately underlies the figurative metaphor.)
  "Those shysters selling the purebreds are running quite a mill over there, eh?"
• (figurative, derogatory) An institution or pseudo-institutional business awarding credentials (such as diplomas, degrees, certificates, or certifications) of either dubious value or fraudulent nature; one selling essays or other documents for the buyers (usually students) to fraudulently pass off as their own.
  "Those shysters cranking out the "IT training certificates" are running quite a mill over there, eh?"
• (informal) An engine.
  "Under the hood is a mill that you and I can't afford — a nitrous-blown hemi with custom heads."
• (informal, archaic) A boxing match or fistfight.
  "They were betting big on a great mill, but they didn't realize that the fix was in."

verb

• (transitive) To grind or otherwise process in a mill or other machine.
  "to mill flour"
• (transitive) To shape, polish, dress or finish using a machine.
• (transitive) To engrave one or more grooves or a pattern around the edge of (a cylindrical object such as a coin).
• (intransitive, followed by around, about, etc.) To move about in an aimless fashion.
  "I didn't have much to do, so I just milled around the town looking at the shops."

noun

• One thousandth part.
  "For this task, I prefer the plastic sheeting that is 10 mills thick."
• One thousandth part.
  "For this task, I prefer the plastic bars that are 10 mills in diameter."

noun

• (informal) Alternative form of mil (“million”).