M, 13th letter of the alphabet, usually representing a bilabial nasal as in the English much. It corresponds with the Greek mu. M is the Roman numeral for 1,000.

Motala ström is the river system that drains lake Vättern, the second largest lake in Sweden, into the Baltic Sea in Norrköping. It is named from the city Motala where it begins. In the early 19th century, the Göta Canal was constructed in parallel with Motala ström.