Look up C4 or c4 in Wiktionary, the free dictionary.

C4, C04, C.IV, C-4, or C-04 may refer to:

Places

• Caldwell 4 or NGC 7023 or Iris Nebula, a reflection nebula in the constellation Cepheus
• Circumferential Road 4 or C-4, an arterial road of Manila, Philippines
• Ken-Ō Expressway, a road in Japan (includes some sections of Shin-Shōnan Bypass)
• Omotesandō Station, a Tokyo Metro subway station (station number: C-04)

People

• C4 (rapper), a rap music producer from Birmingham, England
• Clarence Mitchell IV, American radio host and former politician
• Chris Turner, sometimes credited as Chris Heiner, a.k.a. "C4", Australian musician, part of Modern Day Poets

Computing

• C4 (conference), a Macintosh software developers conference
• C4 Engine, a next-generation 3D game engine
• C4 model (software), a graphical notation technique for diagramming software architecture
• Cx4 chip, an add-on microprocessor chip employed by certain Super NES game cartridges (often incorrectly referred to as the C4 chip)
• Controlled collapse chip connection or flip chip, a method for interconnecting semiconductor devices
• VIA C4, a planned design of central processing unit for a personal computer

Arts, entertainment, and media

Music

• C4 (American band), a neo-classical metal band set up by Michael Angelo Batio
• C4 (French band), French boyband
• C4 (mixtape), mixtape by American rapper Kendrick Lamar
• C₄, scientific pitch notation for the note "Middle C" (261.626 Hz)
• C4 Records, a record label
• Tha Carter IV, album by American rapper Lil Wayne

Other uses in arts, entertainment and media

• C4 (New Zealand TV channel), a former New Zealand television music channel
• 1. c4, also called the English Opening, a chess opening
• The abbreviation for British TV channel Channel 4.

Mathematics, science and technology

Biology

• C4: an EEG electrode site according to the 10-20 system
• Apolipoprotein C4, a protein encoded by the APOC4 gene
• c4 antisense RNA, a non-coding RNA
• ATC code C04 Peripheral vasodilators, a subgroup of the Anatomical Therapeutic Chemical Classification System
• C₄ carbon fixation, a pathway for carbon fixation in photosynthesis that produces C4 plants
• Cervical spinal nerve 4, a nerve originating in the neck
• Cervical vertebra 4, one of the cervical vertebrae of the vertebral column
• C04, oral cancer ICD-10 code
• Complement component 4, a protein involved in the intricate complement system, encoded by C4A or C4B gene in humans
• C₄ fragments, one of the types of products of catabolism pathways

Mathematics

• ${\displaystyle C_{4))$, the cyclic group of order 4
• C4, the fourth pure "core" module in the Edexcel A-level mathematics examination

Other uses in science and technology

• C4, butyl-type hydrocarbon chain, a type of four-carbon molecule, especially in C4 reversed-phase chromatography columns
• Cluster 4, an ESA satellite that studies the Earth's magnetosphere over the course of an entire solar cycle

Organizations

• C4 (Colombia), a political party in Colombia
• C4, a social welfare non-profit entity organized under section 501(c)(4) of the U.S. Internal Revenue Code
• Churches Covered and Connected in Covenant, a religious association founded by Archbishop LeRoy Bailey Jr.
• Craiova Group, a cooperation project of four European states

Sports

• C4 (classification), a Paralympic cycling classification
• C-4, professional wrestler Paul Burchill's name for his finishing move, a moonsault uranage
• C4, an abbreviation for a four-man Sprint Canoe, see Canoe racing
• C4, a term used to refer to the UEFA Intertoto Cup, a football competition (mainly used in non-English speaking countries)
• C4 level, a challenge square dance program at the Challenge 4 level

Stationery

• C4, an international standard paper size (229 × 324 mm), defined in ISO 216
• C4, the envelope size matching the A4 paper size

Vehicles

Aircraft

• C-4, the US Army designation of the Ford Trimotor
• AEG C.IV, a German World War I reconnaissance aircraft
• AGO C.IV, a 1917 German reconnaissance aircraft
• C-4 Academe, the military version of Gulfstream I twin turboprop business aircraft
• C-4 Argonaut, a Canadair aircraft derived from the Douglas DC-4
• Cierva C.4, a 1922 Spanish experimental autogyro
• DFW C.IV, a 1916 German reconnaissance aircraft
• Flight Design C4, a four-seat light aircraft
• Fokker C.IV, a 1923 Dutch two-seat reconnaissance aircraft
• Rumpler C.IV, a 1917 German single-engine, two-seater reconnaissance biplane

Automobiles

• C4, a class of Audi 100 and Audi A6 cars
• Chevrolet Corvette C4, the fourth production design of the Chevrolet Corvette
• Citroën C4, a car made by Citroën
• Coloni C4, a Formula One car built by Enzo Coloni Racing Car Systems
• Sauber C4, a Sauber sportscar
• Spyker C4, a Spyker car

Locomotives

• Bavarian C IV, an 1884 German steam locomotive
• GS&WR Class C4, a Great Southern and Western Railway Irish steam locomotive
• LNER Class C4, a class of British steam locomotives

Ships

• HMS C4, a British C class submarine of the Royal Navy
• Type C4 ship, merchant cargo ships of United States Maritime Commission "C" design
• USS C-4 (SS-15), a United States C class submarine of the United States Navy
• USS Philadelphia (C-4), a protected cruiser of the United States Navy

Vehicle components

• Ford C4 transmission, an automatic transmission
• Menasco C4, a 1930s 4-cylinder, air-cooled, in-line, inverted, aero-engine

Weapons

• C-4 (explosive), a type of plastic explosive
• Hafdasa C-4, an Argentine submachine gun

Other uses

• C4, a variation of Command and control, meaning "Command, Control, Communications and Computers"
• C4, the monogram of Christian IV of Denmark, used in the city arms of Kristianstad, Sweden since 1622
• C4 Extreme, a sports nutrition supplement product line by Cellucor, which includes C4 energy drinks.