nano- This prefix, which denotes one-billionth of a unit, is not followed by a hyphen: nanosecond.

NASA Acceptable in all references for National Aeronautics and Space Administration.

Native American Acceptable for those in the U.S. American Indian is also acceptable. Where possible, be precise and use the name of the tribe: The Navajo (also known as the Diné) are the second largest Native American tribe in the U.S. Russell Means was a Lakota activist and founder of the American Indian Movement (AIM).

nationwide No hyphen. Also: campuswide, collegewide, statewide, worldwide.

New York City Spell out in running text. Identify the borough if pertinent (Manhattan, Brooklyn, the Bronx, Queens, Staten Island).

NGO Usually refers to a nonprofit, humanitarian organization. Use sparingly and only in second references for nongovernmental organization.

9/11 See Sept. 11.

non- In general, no hyphen is used after this prefix, unless it is followed by a proper name: noncredit, nonfiction, non-English titles. See Words Formed with Prefixes under General Style Preferences.

none This word may take either a singular or a plural verb. If it is followed by a singular noun, treat it as a singular: none of the building was painted; if by a plural noun, treat it as a plural: none of the buildings were painted.

nonprofit Use instead of not-for-profit.

notwithstanding One word. Less formal alternatives include despite and although.

numerous This is typically a bloated word for many.