Meridian
Meridian or a meridian line (from Latin meridies via Old French meridiane, meaning “midday”) may refer to

Science
Meridian (astronomy), imaginary circle in a plane perpendicular to the planes of the celestial equator and horizon
Central meridian (planets)
Meridian (geography), an imaginary arc on the Earth's surface from the North Pole to the South Pole
Meridian arc, the distance between two points with the same longitude
Prime meridian, origin of longitudes
Principal meridian, arbitrary meridians used as references in land surveying
Meridian line, used with a gnomon to measure solar elevation and time of year
Autonomous sensory meridian response, a static-like or tingling sensation on the skin

Places
Cities and towns
Meridian, California (disambiguation), U.S., multiple California towns named Meridian
Meridian, Colorado, U.S.
Meridian Village, Colorado, U.S.
Meridian, Florida, U.S.
Meridian, Georgia, U.S.
Meridian, Idaho, U.S.
Meridian, Mississippi, U.S.
Meridian, Nebraska, U.S.
Meridian, New York, U.S.
Meridian, Oklahoma (disambiguation), U.S., multiple Oklahoma towns named Meridian
Meridian, Pennsylvania, U.S.
Meridian, Seattle, Washington, U.S.
Meridian, Texas, U.S.

Townships
Meridian Township, Clinton County, Illinois, U.S.
Meridian Charter Township, Michigan, U.S.

Buildings
Meridian (Amtrak station), or Union Station, Meridian, Mississippi, U.S.
Meridian Mall, Meridian Township, Michigan, U.S.
Meridian Mall, Dunedin, New Zealand
Meridian Hall (Washington, D.C.), listed on the National Register of Historic Places in Washington, D.C., U.S.
Meridian Manor, listed on the National Register of Historic Places in Washington, D.C., U.S.
Meridian Mansions, listed on the National Register of Historic Places in Washington, D.C., U.S.

Other places
Lake Meridian, Kent, Washington, U.S.
Meridian Creek, a stream in Alaska, U.S.
Meridian Glacier, Graham Land, Antarctica
Meridian Peak, Eagles Nest Wilderness, near Vail, Colorado, U.S.
Meridian Plantation, a quail-hunting plantation in Leon County, Florida, U.S., established in 1915

Arts and entertainment
Print
Meridian (novel), 1976 novel by Alice Walker
Meridian (comics), 2000–2004 comic book series published by CrossGen
Meridian (W.I.T.C.H.), a fictional realm in the Italian comic book series W.I.T.C.H.
Meridians: Feminism, Race, Transnationalism (est. 2000), an interdisciplinary peer-reviewed feminist journal

Film and television
Meridian: Kiss of the Beast, 1990 horror and romance film directed by Charles Band
"Meridian" (Star Trek: Deep Space Nine), 1994 episode of the series
"Meridian" (Stargate SG-1), 2002 episode of the series
Meridian (film), 2016 film noir thriller directed by Curtis Clark
ITV Meridian (formerly Meridian Broadcasting), ITV station for the south and south-east of England

Music
Meridian Records, record label
Meridian Dawn, modern death metal band
Meridian Green, California-based folk musician
Meridian, 1997 album by Ian Pooley
Meridian (Miriam Yeung album), 2007 album by Miriam Young
Meridian (album), 2012 album by Pinegrove
"Meridian", 2017 song by Odesza from A Moment Apart

Other art
Meridian (Hepworth), 1960 bronze sculpture by British artist Barbara Hepworth

Business
Meridian Audio, British manufacturer of audio equipment
Meridian Credit Union, credit union based in Ontario, Canada
Meridian Energy, New Zealand electricity generation and electricity retailing company
Nortel Meridian, popular PBX telephone system

Education
Meridian High School (disambiguation)
Meridian Technology Center, Stillwater, Oklahoma, United States

Transportation
Meridian (train), British Rail Class 222 trains
Meridian (commuter rail), former commuter rail service in Germany operated by the Bayerische Oberlandbahn
MS Meridian, cruise ship constructed in 1961
Meridian (shipwreck), sunken schooner in Lake Michigan
Piper Meridian, turboprop model of the Piper PA-46 aircraft
Meridian LRT station, an LRT station on the Punggol LRT line East Loop in Singapore
Meridian Airways, a defunct Ghanaian airline

Other
Bill Meridian (fl. 1972–1983), a financial astrologer
Meridian (Chinese medicine), traditional Chinese medical theory, often employed in acupuncture
Meridian (horse), American Thoroughbred racehorse, winner of 1911 Kentucky Derby
Meridian (Nosgoth), the capitol of Nosgoth in Blood Omen 2: Legacy of Kain
Meridian (perimetry, visual field), polar coordinate system for the visual field
Meridian (satellite), a series of Russian military communications satellites
Meridian F.C., English non-league football club
Meridian Hospital, a private hospital in Port Harcourt, Rivers State, Nigeria
Meridian Lossless Packing, a lossless audio compression technique used in DVD-Audio, HD DVD, and many Blu-ray discs

See also
Meridian 59, online game
Meridian Hill Park, a park in Washington D.C., U.S.
One Meridian Plaza, an office building that burned down in 1991 in Philadelphia, Pennsylvania, U.S.