L1

Etymology 1
From.

Noun

 * 1) Mother tongue; someone's native language; own language.

Translations

 * French:
 * German: L1
 * Japanese: L1

Noun

 * 1)   located between the larger and smaller objects along a line connecting the two.

Related terms

 * Lagrange point, L2, L3, L4, L5

Etymology 3
From 1.

Noun

 * 1)  Short for first level in various contexts.
 * 2)  The first-level cache of a processor, closer to the processor than the second-level cache.
 * 3)  The physical layer in the seven-layer OSI network model.
 * 1)  The physical layer in the seven-layer OSI network model.

Usage notes
The first level cache is more often written as L1 cache than as L1 except when used attributively in writing meant for a technical audience.