Definition

1. Proper noun:
   • A major river in the United States: The Missouri River is the longest river in the United States. It originates in the state of Montana and flows generally southeast until it joins the Mississippi River near Saint Louis, Missouri. The combined Missouri-Mississippi river system is the third-longest in the world.

Usage Examples

• Proper noun:
  • The Lewis and Clark Expedition followed the Missouri River for much of their journey westward.
  • Flooding along the Missouri River can affect many states.
  • The Missouri River is a major tributary of the Mississippi.

Advanced Usage

• "The Big Muddy": A common nickname for the Missouri River, referring to its high sediment load.
  • Early explorers called the Missouri River "The Big Muddy" because of its brown, silt-filled waters.

Variants and Related Words

• Missourian (noun): A person from the state of Missouri, which is named after the river.
  • As a Missourian, she grew up near the great river.

Synonyms

• The Big Muddy: (Nickname) The Missouri River.
• Upper Missouri / Lower Missouri: Terms used to describe different sections of the river's course.

Noun

1. the longest river in the United States; arises in Montana and flows southeastward to become a tributary of the Mississippi at Saint Louis
   • The Missouri and Mississippi Rivers together form the third longest river in the world