CH

CH, Ch, cH, or ch may refer to:

Arts and entertainment

• Television channel (sometimes abbreviated as "ch." for television and cable stations)
• CollegeHumor, a comedy website
• E!, a defunct Canadian television system that went by the name CH from 2001 to 2007

Businesses

• Bemidji Airlines (IATA code)
• Carolina Herrera, a fashion designer based in New York
• Columbia Helicopters, an aircraft manufacturing and operator company based in Aurora, Oregon, United States

In language

• Chamorro language: ISO 639 alpha-2 language code (ch)
• Ch (digraph), considered a single letter in several Latin-alphabet languages

Science and technology

Chemistry

• The methylidyne radical (carbyne) ⫶CH
• The methylidyne group ≡CH
• The methanetriyl group >CH−
• The methine group (methanylylidene, methylylidene) =CH−

Mathematics and computing

• Chomsky hierarchy, in computer science, a containment hierarchy of classes of formal grammars
• Continuum hypothesis, in set theory
• Hyperbolic cosine, in mathematics, a hyperbolic function, ch(x) = cosh(x)
• Curry–Howard correspondence, the relationship between computer programs and mathematical proofs
• CH register, the high byte of an X86 16-bit CX register
• Ch, a cross-platform C/C++ interpreter

Medicine

• Cluster headache
• Cholesterol
• Congenital hypothyroidism

Military technology

• Cargo helicopter (U.S. military helicopter alpha-numeric prefix)
• Chain Home, a World War II radar array
• Heavy cruiser (U.S. Navy ship code CH, standing for "Cruiser, Heavy")

In other sciences

• Clay of high plasticity (USCS soil type CH)

Places

• Confoederatio Helvetica, the formal name for Switzerland, Latin in origin
  • ISO country code for Switzerland
  • .ch, the Internet country code top-level domain for Switzerland
• CH postcode area; the Chester postcode area in the UK
• Chihuahua (state), the State of Chihuahua, Mexico
• Conservation Halton, in Ontario, Canada
• People's Republic of China (FIPS and NATO country code CH)

Other uses

• Chain (length), a unit of linear measure in the Imperial system
• Championship (dog), a dog qualifying for a championship at a conformation show, prefixed "Ch."
• Christ's Hospital, Horsham, West Sussex
• Companion of Honour, a British and Commonwealth honour
• Chaudhary, an honorific used in the Indian and Pakistani Punjab regions
• Metres above the Sea (Switzerland), an elevation reference system
• The logo for the Montreal Canadiens ice hockey team, derived from its French name, Les Canadiens de Montréal