LD

• Lighting designer, a person in charge of lighting in theatre

Film and television

• Lorraine "L.D." Delacorte, a character on the TV series Degrassi
• Larry David, sometimes referred to as L.D. on the television show Curb Your Enthusiasm
• Latin Disciples, a fictional gang in television series Day Break
• Living Dangerously (wrestling series), an Extreme Champion Wrestling pay-per-view event (ECW PPV)
• Low-definition television (LDTV)
• "-LD", a United States call sign suffix signifying a low-power digital television station
• LaserDisc or MCA Discovision is a 12 inch Analog Video optical disc

Music

• Lil Dicky (born 1988), American rapper
• Little Doses, a Scottish alternative rock band
• Luis Dubuc (born 1985), American musician
• LD (rapper), British rapper
• Lemon Demon, American musical project and band

• Air Hong Kong (IATA code LD)
• Light Dragoons, a British Army cavalry regiment
• Línea Turística Aereotuy (IATA code LD)
• London Drugs, a Canadian pharmacy and retail chain
• Louis Dreyfus Company, a French commodities trading firm

Contract law

• Liability damages
• Liquidated damages

Currencies

• Liberian dollar, the currency of Liberia
• Libyan dinar, the currency of Libya
• Liberty dollar (private currency), produced in the US

Products

• LD (cigarette), a brand of cigarette

• LD postcode area, also known as the Llandrindod Wells postcode area, in Wales
• Lakshadweep, India (ISO 3166-2 code LD)
• County Longford, Ireland (code LD)

• Liberal democracy, a form of government based on rule of the people (democracy) tempered by the rule of law and natural rights (liberalism)
• Lincoln-Douglas debate, a form of debate
• Liberal Democrats (UK), a UK political party
• Lord, a peer of the realm in the United Kingdom

Astronomy

• Lilian day, a variant of the Julian day
• Lunar distance, the distance between the Earth and the Moon, used as a general measure of distance

Biology and medicine

• Lactate dehydrogenase, an enzyme in plants and animals
• Lateral dorsal nucleus of thalamus, an anatomic structure of the brain
• Learning disability, a condition that can impair learning through standard methods
• Lethal dose, an indication of the lethal toxicity of a given substance or type of radiation
• Licensed Dietitian
• Linkage disequilibrium, in genetics, when alleles occur together more often than they would by chance
• Lucid dreaming, a dream in which one is conscious of dreaming as it is happening

Electronics and computing

• ld, an instruction on a Z80 CPU
• ld (Unix), the linker command on Unix and Unix-like systems
• Laser diode, semiconductor laser-emitting device
• LaserDisc, an obsolete optical disc video/data format and predecessor to DVD
• Levenshtein distance, a string metric for measuring the difference between two sequences.
• Line Dubbed, a term for unlicensed copies of films with an audio track, which has been ripped from the line out connection of a projector
• Linked data, a method of publishing structured data so that it can be interlinked and become more useful
• The 'Linked Document' in the NISO standard Content Profile/Linked Document, a data serialisation format

Telecommunications

• Long-distance calling, a telephone call charged at a higher rate
• Loop Disconnect dialing

Other

• (chemistry) D/L nomenclature, used in naming chemical compounds
• (linguistics) Language Development, the changes that take place in language, speech & communication in the context of children's development
• (manufacturing) Linz-Donawitz process, a widely used process in Basic oxygen steelmaking
• (mathematics) Binary logarithm, , from the Latin logarithmus dualis
• (military) Laser designator, used by the military for targeting
• (physics) London dispersion force, weak intermolecular forces
• (statistics) Listwise deletion, a method of handling missing data

• (communications) Lincoln-Douglas debate format
• (sociology) Long-distance relationship
• (sports) Line drive, in baseball
• (sports) Ludum Dare, a game development competition