L (disambiguation)

L, or l, is the twelfth letter of the English alphabet.

L or l may also refer to:

Left (direction)
L, length in general (often the longest dimension, as opposed to width, height, or depth)
- Horse length, used in horse racing
- Boat length, used in rowing
L, l or ℓ, litre, a unit of volume
l, abbreviation for liquid
L, the Roman numeral representing the number 50
Loser (hand gesture)

Finance

Ancient Roman libra (translated as "pound"), a weight measure with derivative units denoted with "L" or a derived character:
- Pound (currency), a number of currencies from the British Empire, abbreviated £ or (historically) "l", "L", or " ${\mathfrak {L}}$ ". (Some fonts use a two-bar version resembling the lira sign ₤.)
- Livre (disambiguation), a number of currencies from the French Empire, with the original abbreviated "£", "₶", or "lt"
- Lira, a number of currencies from Italy and the Ottoman Empire, abbreviated as ₤
Loews Corporation, by NYSE ticker symbol
Miscellaneous, when used as the fifth letter or behind-the-dot notation on the NASDAQ and NYSE ticker symbols

Low-pressure area, in meteorology
Canon L lens, in photography
L or ${\mathcal {L}}$ , notation for a Lagrangian (disambiguation), in math and physics
L band (disambiguation), in telecommunications

$L$ , constructible universe, a particular class of sets which can be described entirely in terms of simpler sets
L-function, meromorphic function on the complex plane
${\mathcal {L}}$ , Laplace transform
${\mathcal {L}}$ , likelihood function
ℓ^p space, the space of sequences with a finite p-norm
L^p space, a function space defined using a natural generalization of the p-norm for finite-dimensional vector spaces
L, symbol for basic provability logic
L (complexity), a complexity class in computational complexity theory
L-notation, used for running times of subexponential algorithms
Android L, code name for Android Lollipop

L, Langmuir (unit), a unit of exposure to a surface, used in ultra-high vacuum surface physics
ℓ, azimuthal quantum number
Angular momentum
Inductance, the ratio of the magnetic flux to the current in an electrical circuit
Latent heat
Mean free path, the average distance traveled by a moving particle between successive collisions
Luminosity
Class L, a stellar classification
Galactic longitude (l), in the galactic coordinate system

Avogadro constant, in some German scientific literature
Leucine, an α-amino acid
l-, prefix indicating a levorotary compound
L-, prefix indicating of absolute configuration
- L-amino acid
Lewisite, a blister agent
Carl Linnaeus, in botanist author citations (L.)
Haplogroup L (Y-DNA)
Vertebra in the lumbar region of the spinal cord
ATC code L Antineoplastic and immunomodulating agents, a section of the Anatomical Therapeutic Chemical Classification System

L (novel), a 1999 novel by Erlend Loe
[ʟ], the velar lateral approximant (IPA notation)
[l], the alveolar lateral approximant (IPA notation)
The Cyrillic palochka (Ӏ)
Ḷ, a letter derived from L with a diacritical dot below
The "low" or common language in a diglossia
${\mathfrak {L}}$ , a siglum for the Vetus Latina version of the Bible
Leaf (books) ("l." or ℓ), an alternate numbering for books, in contrast to "p." for pages
Specification for a line of text, for example "l. 3" is the third line of text

L (French singer), French singer-songwriter
L (entertainer), vocalist of Korean boy band Infinite
L Marshall, British singer credited as L on the Wretch 32 song "Traktor"
Lesure Number, music catalogue identifier for the compositions of Claude Debussy
L Number, classification of the compositions of Franz Benda according to the catalogue of Douglas A. Lee

L (Los Angeles Railway)
Chicago "L", a rapid transit system in Chicago
L (New York City Subway service)
L Line (Los Angeles Metro)
L (SEPTA Metro)
Transilien Line L, a line of the Paris transport network
The official West Japan Railway Company service symbol for:
- Maizuru Line
- Uno Line
L Taraval (San Francisco Muni)
LB&SCR L class, a British tank locomotive on the London, Brighton, and South Coast Railway