- loess clay
- logwood
- longitudinal stress
- longitudinal valley
- longleaf pine
- look box
- loom oil
- loop
- loop seal
- loose
- loose black
- loose circulation
- loose coupling
- loose ground
- loose joint
- loose plant
- loose reel
- loose roof
- loose sand
- loosen
- loosening
- location map
- lock ball
- locked
- locking device
- locomotor
- log strip
- logarithmic creep
- lomax process
- long chain
- long residuum
- longitudinal baffle
- longitudinal moraine
- lose returns
- low concentration
- low distillation
- low-grade
- lower bainite
- lower bend
- lower valve
- lower wall
- lowering in
- lubricant
- lubricating can
- lubricating cup
- lubricating film
- lubrication chart
- lubrication diagram
- lubricity
- long measure
- Long run
- long stroke
- long ton
- loss factor
- lossy compression
- lost hole
- lost oil
- lost pressure
- lost record
- lough
- low
- low coast
- low fermentation
- low flow
- low gear
- lot
- low dip
- low explosive
- low ground
- low-boiling
- lowdown pump
- lower block
- lower reach
- lower sample
- lowland
- lowland desert
- lubricant film
- lubricating graphite
- lubricating nipple
- lubricating power
- lubricator
- Ludian stage
- Ludiovian stage
- ludlamite
- ludwigite
- luff tackle
- lug
- luggage carrier
- lumber
- luminescence temperature
- luminous paint
- lump coal
- lump coke
- lump ore
- lumper bar
- luseladite
- lussatite
- lustrous
- lute
- lutecite