LD
LD may refer to:
In science and mathematics:
- Lethal dose#, where "#" represents the percentage of test organisms killed by a specific dosage (of drugs, radiation, etc.), e.g. half will die at LD50
- The logarithm of base 2,
, from the Latin logarithmus dualis - Lunar distance (astronomy), the distance between the Earth and the Moon and a measure of navigation
- Linkage disequilibrium, when distinct alleles appear together more often than by chance (thanks to founder effects, etc.) in genetics
- lactate dehydrogenase, an enzyme in plants and animals
- London dispersion forces, weak intermolecular forces
- Lateral dorsal nucleus of thalamus
In technology:
- Laser diode, semiconductor laser-emitting device
- Laserdisc format, an obsolete optical disc video/data format and predecessor to Digital Video Disc (DVD)
- ld (Unix), the linker command on Unix and Unix-like systems
- Long distance, a telephone call to another area sufficiently far away to be charged at a higher rate
- Loop Disconnect dialing
- ld, an instruction on a Z80 CPU
- Line Dubbed, a term for pirate copies with an audio track, which has been ripped from the line out connection of a projector
- Ladder diagram (disambiguation), various meanings
- Linz-Donawitz process, a widely used conversion process in steelmaking
- Linked data, a method of publishing structured data so that it can be interlinked and become more useful
In politics:
- Liberal democracy, a form of government based on rule of the people (democracy) tempered by the rule of law and natural rights (liberalism)
- A form of debate (Lincoln–Douglas debate)
- Liberal Democrats, a UK political party
In television:
- Lorraine "L.D." Delacorte, a character from the Degrassi series played by Amanda Cook
- Larry David, sometimes referred to as L.D. in the television show Curb Your Enthusiasm
- Latin Disciples, the name of a gang in television series Day Break
- Low-definition television (LDTV)
In music:
- Little Doses, a Scottish alternative rock band
- Luis Dubuc
In contracts:
- Liability Damage
- Liquidated Damages, a figure in contract law
LD can also refer to:
- LD, the ISO 3166-2 code for Lakshadweep, India
- LD, the code for Longford, Ireland
- LD postcode area, also known as the Llandrindod Wells postcode area, in Wales
- Learning disability, a condition that can impair learning through standard methods
- Liberian dollar, the currency of Liberia
- Libyan dinar, the currency of Libya
- Liberty dollar, the private currency by norfed
- Licensed Dietician
- Light Dragoons, a British Army cavalry regiment
- Lighting designer, the person in charge of lighting in theatre
- Lincoln–Douglas debate, a form of debate
- Line Drive, a trajectory-related inference and statistic of a batted ball in baseball
- Lilian day, a variant of the Julian day
- Air Hong Kong and Linea Turistica Aerotuy, airlines with IATA code LD
- LD (cigarette), a brand of cigarette from the Gallaher Group
- Living Dangerously, an ECW PPV
- Listening device, used in covert investigations
- Long distance relationships
- Louis-Dreyfus Group, a French commodities trading firm
- Lucid dreaming, a dream in which one is conscious of dreaming as it is happening
- Ludum Dare a rapid game development competition
- Lynsey Dyer, an American freeskier and Big Mountain skier
Ld (Capital L with a lower case "d") is the abbreviated form of: