CT or ct may stand for:
Carat (purity) (ct), a measure of the purity of gold and platinum alloys
Carat (mass) (ct), a unit of mass used for measuring gems and pearls.
Cardiothoracic Surgery, the field of medicine specializing in chest surgery
Center tap, a wire that is connected halfway along one of the windings of a transformer, inductor or a resistor
Centime (ct), French for "cent", used in English in several Francophone countries
Central Time zone, a time zone in Canada, the United States, and Mexico
Civil Air Transport IATA code
Chrono Trigger, a console role-playing game created by Square for the Super NES
Crazy Taxi, a driving video game for multiple platforms. Also includes the series of the same name.
Combustion turbine, a rotary engine that extracts energy from a flow of combustion gas
Computed tomography, a.k.a. CAT scan, a medical imaging method
Counter-terrorism, the practices, tactics, and strategies used by governments and militaries to fight terrorism
Court (ct), postal abbreviation.
Cryptologic technician, a United States Navy enlisted rating or job specialty
c't, a German computer magazine, standing for "Computer Technik"
c*m tempore (c.t.), Latin for "with time", meaning (Austrian/German/Swiss or Scandinavian university's lecture starts) 15 minutes later
Transparency (optics) (see-through)
Cryme Tyme, a professional wrestling stable working for WWE's RAW brand
Closet Trekkie, the secret loving of the TV franchise, Star Trek
Cody Travers, a video game character
Characteristic Time, The Characteristic Time (CT) test checks for the spring effect of a golf club by measuring the duration in which a pendulum object stays in contact with the club face. The CT limit is 257 microseconds (239 microseconds plus a tolerance of 18 microseconds).
Intel Ct, a SIMD `Multithreading programming model developped by Intel.
Calgary Transit, the public transit service in Calgary, Alberta, Canada
Canadian Tire, one of Canada's largest publicly traded companies and operates an inter-related network of businesses engaged in retailing, financial services and petroleum.
Central Trains, a train operating company in the United Kingdom
Česká televize (ČT), the public television broadcaster in the Czech Republic
Combined Transport Inc., a heavy haul trucking service based out of Central Point, Oregon, United States
ChrisTek Coding (ctc), a web design firm
CT, the largest registered agent firm in the world.
Communist Terrorists (also "Charlie Tango") - a term used by the British during the Malayan Emergency to refer to the Malayan Races Liberation Army.
Counter-Terrorists, One of the two possible teams in the popular game Counter-Strike.
Canton and Enderbury Islands (via obsolete ISO 3166 country code), part of the Phoenix Islands in the Pacific Ocean
Cape Town, the legislative capital of South Africa
Catania, the capital city of the province of Catania, in Sicily, Italy
Central African Republic (via FIPS Pub 10-4 code and obsolete NATO digram)
Connecticut, via United States postal abbreviation
Taken from: http://en.wikipedia.org/wiki/CT