Long distance, a telephone call to another area sufficiently far away to be charged at a higher rate.

Learning disability, a condition that can impair learning through standard methods

Liberal democracy, a form of government based on rule of the people (democracy) tempered by the rule of law and natural rights (liberalism).

Lethal Dialect rapper

ld, an instruction on a Z80 CPU.

Lucid dreaming, a dream in which one is conscious of dreaming as it is happening.

Lilian day, a variant of the Julian day.

London dispersion forces

Lighting designer, the person in charge of lighting in theatre.

Lincoln-Douglas debate, a form of debate.

Larry David, sometimes referred to as L.D. in the television show Curb Your Enthusiasm.

Lorraine "L.D." Delacorte, a character from the Degrassi series played by Amanda Cook.

Liberal Democracy summary and related information.

Latin Disciples, the name of a gang in television series Day Break

Linkage disequilibrium, when seemingly independent alleles have different rates of appearance (thanks to fitness concerns, etc.) in genetics.

The logarithm of base 2, <math>\mathrm{ld}(x)=\log_2(x)</math>, from the Latin logarithmus dualis.

ld (Unix), the linker command on Unix and Unix-like systems.

Lethal dose, the percentage of test organisms killed by a specific dosage (of drugs, radiation, etc.).

Long distance relationships

Linkdead, shorthand for "disconnected from the server" in some online activities and games.

Lunar distance, the distance between the Earth and the Moon and a measure of navigation.

Laserdisc format, an obsolete optical disc video/data format and predecessor to Digital Video Disc (DVD).

Line Dubbed, a term for pirate copies with an audio track, which has been ripped from the line out connection of a projector

Air Hong Kong and Linea Turistica Aerotuy, airlines with IATA code LD.

Liquor drink, a drink composed of a Distilled beverage and a drink mixer.

Lord, a peer of the realm in the United Kingdom.