L/C (Letter of Credit)

Labile Complex

Labour (Labor)

Labour (Labor) Cost

Labour (Labor) Day (or May Day)

Labour (Labor) Dispute

Labour (Labor) Productivity

Labour (Labor) Turnover

Labour Price Index (LPI)

Lacquer

Ladder Diagram (Relay Ladder Diagram)

Lading

Lag

Lag Correlation

Lager

Lagging Indicator

Lagging Metric

Lagoon

Laissez Faire Leadership

Laminar Flow (or Streamline Flow)

Laminate

Lamination

Lamp

LAN (Local Area Network)

Land

Land Degradation

Land Reclamation

Land Use Planning

Landfill

Landmark

Landscape

Lane

Langelier Index

Langley (L)

Language

Lanthanide or Lanthanoid

Lanthanum (La)

Lap Joint Flange

Laplace Equation

Lapse

Laser Testing Methods (LM)

LASH (Lighter Aboard Ship)

Lashing and Securing

Late Foetal Death

Latent

Latent Cooling Load

Latent Failure

Latent Heat

Latent Heat of Vaporization

Latent Variable

Lateral

Latex

Latex Paint

Latex Rubber

Latitude (lat)

Lattice

Lattice Energy 

Law

Laws of Science (Scientific Laws)

Lawrencium (Lr formerly Lw)

Laws of Thermodynamics

Lawsuit

Laydown Area

Layer

Layer of Protection

Layering

Layoff

Layout

Layout Drawing

Layout of Representation

Laytime

LDL (Low Density Lipoprotein)

Le Chatelier′s Principle

Leaching

Lead

Lead (Pb)

Lead Acid Battery

Lead Time

Leadership

Leadership (Management) Type

Leading Edge

Leading Indicator

Leak

Leak Test

Leakage

Leaking Electricity

Lean

Lean Gas

Lean Management

Lean Oil

Lean Production

leap

Lease

Leave

Ledger

Leeway

Leftover

Leg

Legal

Legal Duty

Legal Entity

Legal Tech (Legal technology)

Legend

Legionella

Legislation

Legitimate

Legitimation or Legitimisation

Lemon Law

Length

Lentic Ecosystem

Leprosy or Hansen's disease (HD)

Lesion

Lessons Learned (LL)

Lethal

Lethal Concentration (LC)

Lethal Dose (LD)

Lethal Service

Letter

Letter of Indemnity (LOI)

Levee

Level of Concern (LOC)

Level of Effort (LOE)

Level of Schedule

Levelised Energy Cost (LEC)

Levelised Life Cycle Cost

Levelling

Leverage

Leveraged Buyout (LBO)

Levy

Lewis Acid

Lewis Base

Lewis Symbol and Structure

Lewis Theory

Lexical

Lexicon

LHV (Lower Heating Value)

Liability

Liability Insurance

Liberalisation (or Liberalization)

LIBOR (London Interbank Offered Rate)

Licence (License in USA)

License

Licensed process Design Package

Licensing

Lien

Life

Lift

Life Cycle (or Lifecycle)

Life Cycle Assessment (LCA)

Life Cycle Cost

Life Cycle Cost Analysis (LCCA)

Life Cycle Design

Life Expectancy

Life Insurance

Life Length

Life Science

Life Time Cost Analysis

Lifecycle

Lifestyle Exercise

Lifetime

Lifetime Fertility

LiFi (Light Fidelity)

LIFO (Last-in-first-out)

LIFO (Liner In / Free Out)

Light

Light Cloud

Light Crude

Light Ends

Light Gas Oil

Light Pipe

Light Water

Lighting and Distribution Panel Schedule

Lighting Level Calculation

Lightning

Lightning Arrester

Lignite

LIGO (Laser Interferometer Gravitational-Wave Observatory)

LIGO Scientific Collaboration (LSC)

Likelihood

LILO (Liner In / Liner Out)

Limbo

Limestone

Limitation Period

Limited Company (Ltd.)

Limited Impact Incident

Limited Liability

Limited Liability Company (LLC)

Limiting Oxidant Concentration (LOC)

Limnology

Line Commutated Inverter

Line Current

Line List

Line Loss (or Drop)

Line Management

Line Pack

Linear Accelerator

Linear Energy Transfer (LET)

Linear Flow

Linear Fresnel System

Linear Motor

Linear Programming

Liner

Lines of Credit

Linguistics

Lining

Link

Link (Length)

Link Relative

Linking

Lintel

Lip Seal

Lipid

Liquefaction

Liquefied Flammable Gas (LFG)

Liquefied Petroleum Gas (LPG)

Liquid

Liquid Based Solar Heating System

Liquid Electrolyte Battery

Liquid Seal

Liquid To Air Heat Exchanger

Liquid To Liquid Heat Exchanger

Liquidate

Liquidated Damages

Liquidation

Liquidity

Liquidity Risk

Liquidity Trap

List

Listed Building

Literary

Literate

Literature

Lithium (Li)

Lithium Ferrophosphate Battery (or LFP Battery)

Lithium Sulphur Battery (Li-S Battery)

Lithium-Ion Battery (Li-I Battery)

Lithosphere

Litigation

Litmus Paper

Litre (Liter)

Live Steam

Live Vector Vaccine

Livermorium (Lv)

Livestock

Living Quarter

LMC (Liquid Metal Cracking)

LNG (Liquefied Natural Gas)

LNG (Liquefied Natural Gas) Project

LNG (Liquefied Natural Gas) Storage Tank

LNG Membrane Containment System

LNG Price Formation Mechanism

LNGC (Liquefied Natural Gas Carrier)

LO/LO (Lift On/ Lift Off)

Load

Load Analysis

Load Current (A)

Load Factor

Load Flow Analysis

Load Forecast

Load Levelling

Load List

Load Management

Load Profile or Shape

Load Shedding

Load Shifting

Loan

Loan Agreement

Loan Guarantee

Loan Loss Provision

Lobe Pump

Local Content

Local Distribution Company (LDC)

Local Exhaust

Local Government

Locality

Localised Corrosion

Localized Incident

Location

Location Risk

Lockdown

Lockout

Log Law

Logarithmic Mean

Logic Control System

Logic System

Logic

Logistics

Logistics Facility

Logistics Management

Logistics Model

LOI (Letter of Intent)

London Stock Exchange (LSE)

Lone Pair 

Long Term Variation

Long Ton

Longitude (long)

Longwave Radiation

Look Ahead Schedule (Window Schedule)

Loop

Loop Diagram

Loop Reactor

Looping

Loose Fill Insulation

LOPA (Layers of Protection Analysis)

Lorem Ipsum

Lorry

Loss

Loss Adjuster

Loss Event

Loss of Load Probability (LOLP)

Loss Prevention

Lotic Ecosystem

Lotic Water

Lovastatin

Low Alloy Steel

Low Carbon Steel

Low Emissivity Windows & (Window) Film

Low Enriched Uranium (LEU)

Low Pressure Tank

Low Sulphur Fuel Oil (LSFO)

Low Voltage Cutoff (LVC)

Low Voltage Disconnect Hysteresis

Lowe Price Index

Lower Calorific Value (LCV)

Lower Heating Value (LHV)

Lozenge

LPG (Liquefied Petroleum Gas)

LRG (Liquefied Refinery Gases)

LSTK (Lump Sum Turnkey)

LTA (Long Term Agreement)

LTI (Lost Time Injury)

LTIFR (Lost Time Injury Frequency Rate)

LTIIR (Lost Time Injury Incidence Rate)

Lubricant

Lubricator

Lubricator Valve

Lubricity

Luggin Probe

Lumen (Lm)

Lumens/Watt (lpw)

Luminaire

Luminance

Luminance Flux (Luminous Flux)

Luminous

Luminous Intensity

Lump Sum

Lump Sum Contract

Lumpsum Freight

Lupus

Lutetium (Lu)

Lux (lx)

Lymphoma