noun

• (money) A piece of currency, usually metallic and in the shape of a disc, but sometimes polygonal, or with a hole in the middle.
  "...the coins were of all countries and sizes - doubloons, and louis d'ors, and guineas, and pieces of eight..."
• (figurative) That which serves for payment or recompense.
  "The loss of every present advantage to flesh and blood is repaid in a nobler coin."
• (uncountable, figurative) Something in broad circulation or use.
  "Tho’ truths in manhood darkly join, ⁠Deep-seated in our mystic frame, ⁠We yield all blessing to the name Of Him that made them current coin; […]"
• (uncountable, slang, UK, US, African-American Vernacular) Money in general, not limited to coins.
  "She spent some serious coin on that car!"

verb

• (by extension) To make or fabricate (especially a word or phrase).
  "Over the last century the advance in science has led to many new words being coined."

noun

• (US, military) Abbreviation of counterinsurgency.