Delta most commonly refers to:

• Delta (letter), the letter ? or ? in the Greek alphabet, also used as a mathematical symbol
• River delta, a landform at the mouth of a river

Delta also has the following meanings:

Abbreviations

• DELTA (ELT), an advanced diploma in English language teaching
• DELTA (taxonomy), the DEscription Language for TAxonomy

Places

Canada

• Delta, British Columbia (the town located immediately south of the Fraser River delta)
  • Delta (provincial electoral district)
  • Delta (electoral district), a federal electoral district

Nigeria

• Delta State, Nigeria

United States

• Delta, Colorado
• Delta, California
• Delta, Iowa
• Delta, Kentucky
• Delta, Louisiana
• Delta, Missouri
• Delta, Ohio
• Delta, Pennsylvania
• Delta, Utah
• Delta, Wisconsin
• Delta Charter Township, Michigan
• Delta County, any of several

See also: Mississippi Delta (disambiguation)

Science and technology

Astronomy and physics

• Delta baryon, a subatomic particle with spin 3/2
• In Bayer designation, one of the stars in a constellation (e.g., Delta Cygni)
• Delta-v, a term used in astrodynamics for the total 'effort' to change from one space trajectory to another

Aeronautics

• Delta wing
• Delta rocket, a family of launch vehicles
• Delta Formation (Aircraft), a formation flying manoeuvre in the shape of a V

Earth sciences

• Delta switching, the process by which some rivers change their course near their deltas
• Tropical Storm Delta (2005)
• Δ and delta are used to represent epicentral distance in seismology.

Mathematics and computer science

• ? often denotes a difference; ? can represent a small change or amount
• In elementary set theory and Boolean algebras, ? usually denotes the symmetric difference
• An inverted delta (\nabla), known as del or nabla, is used as a vector differential operator
• Kronecker delta, a function of two variables which is 1 when they are equal
• Dirac delta function, a distribution used as an approximation for a spike function
• Delta encoding, a technique in computer communications and version-control
• In formal fuzzy logic, ? denotes a unary connective representing the full truth of a proposition (often called Baaz Delta connective)
• ? indicates a change of state between two before and after state schemas in the Z notation

Mathematical finance

• One of the Greeks (finance) used in option and derivatives pricing representing the rate of change of the option price with respect to changes in the underlying price

Medicine and biology

• Delta (ligand), an activator of the Notch signaling pathway
• Single use of Delta (?) is an abbreviation for the diagnosis of a patient
• Double use of Delta (??) is an abbreviation for the differential diagnosis of a patient

Military

• Delta Force, a U.S. Army special force
• Beredskapstroppen, a Norwegian special police forces team
• Delta class submarine, a Soviet / Russian SSBN submarine series (NATO reporting name)

Companies and products

• Delta Air Lines, a major U.S. airline
• Delta (computer), a Russian ZX Spectrum clone
• Delta Dental, an American dental plan system
• Delta Faucet Company, a plumbing fixtures company
• Delta Holding, an import-export, banking, insurance and retail corporation in Serbia
• Delta Hotels, a Canadian hotel chain
• Delta Machinery, a stationary power tools and equipment company
• Delta Motor Corporation, a South African car manufacturer owned by General Motors
• Delta robot, a specialized type of robot
• GM Delta platform, a compact car automobile platform from General Motors
• Ilford Delta, a photographic film
• Lancia Delta, a rally car made by the Italian company Lancia
• Enfield Cables Ltd, a cable manufacturer
• Delta (pen manufacturer) a fine-writing-instruments manufacturer
• Oldsmobile Delta 88, a car made by the US Company Oldsmobile

Entertainment and fiction

• Delta Goodrem, an Australian singer

• Delta (album), a 2007 studio album by Delta Goodrem

• Delta-S, an industrial band from Camarillo, California
• Delta (computer game), a 1987 horizontally-scrolling shooter computer game
• Delta (TV series), a 1992 TV series starring Delta Burke
• Delta Halo, Halo Installation #5 in the Halo Universe
• Delta FM, a UK radio station
• Delta Quadrant, a quadrant of the Milky Way Galaxy depicted in Star Trek
• Delta Squad, the player's team in Star Wars: Republic Commando
• Delta, a codename used by Jason Bourne in the fiction series The Bourne Identity
• E-103 Delta, a robot in E-Series (Sonic the Hedgehog)
• R·Type Delta, the fourth R-Type game in the series
• EX Delta Species, a Pokémon Trading Card Game expansion
• Delta Flyer, a shuttle craft in the Star Trek TV series Voyager
• Kamen Rider Delta, a Kamen Rider that appeared in the Japanese TV series Kamen Rider 555
• Space Patrol Delta, a fictional organization from the Power Rangers universe
• The Delta Megazord (shaped like a capital ?) is a zord in Power Rangers in Space

Miscellanea

• Delta waves, a low level EEG reading associated with sleep
• Delta Works, a flood-protection works in the Netherlands
• A form of tricycle having two wheels in back and one wheel in front
• The refractory section in the roof of an electric arc furnace (EAF) through which one or more electrodes enter
• Delta, a quadra group used in socionics

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