label-mould

Projecting moulding providing weather protection over a door or window.

label-stop

An ornamental boss at the terminations a hood-mould.

lancet

An arch where the radius is larger than the span.

lancet window

A pointed-arched window.

landing

A flat slab forming the top of a staircase.

leaching

Removal of mineral salts by percolating water.

ledger

A large flat stone capable of spanning a space and carrying a load.

lime putty

Slaked lime produced by mixing hydrated lime and water.

limestone

Sedimentary rock consisting predominantly of calcium carbonate.

lintel, lintol

Load bearing stone spanning across an opening.

loam

Mixture of clay and sand (possibly reinforced with straw).