Meaning
A capital M inside a circle, often used as the sign for a metro or subway station in many cities. It can also stand in for the letter M.
Travellers use it for directions and meeting points near stations: “Meet at the Ⓜ️ exit by the market, 6 pm” It also decorates names and initials starting with M, and some use it as shorthand for million in prices. Pair it with 🚇 to make the metro meaning clear.