APA (7th ed.) Citation

Merriam-Webster, Inc. (1991). Webster's ninth new collegiate dictionary. Merriam-Webster.

Chicago Style (17th ed.) Citation

Merriam-Webster, Inc. Webster's Ninth New Collegiate Dictionary. Springfield, Mass., U.S.A.: Merriam-Webster, 1991.

MLA (9th ed.) Citation

Merriam-Webster, Inc. Webster's Ninth New Collegiate Dictionary. Merriam-Webster, 1991.

Warning: These citations may not always be 100% accurate.