# lambert

/ˈɫæmbɝt/ (US) · /lˈæmbət/ (UK)

Source: https://englishreference.com/word/lambert
Updated: 2026-08-15

## Senses

### 1. unit of brightness

noun · CEFR C2 · Technical

a scientific unit used to measure how much light comes off a surface.

For teachers: a non-SI unit of luminance, defined as the brightness of a surface emitting one lumen per square centimetre.

- The scientist recorded the brightness of the screen in lamberts.
- Although the candela per square metre is the standard SI unit, the lambert is still occasionally encountered in older texts discussing surface luminance.

Usage: Usually abbreviated as 'L' or 'Lb' in technical documentation.

### 2. a name

noun · CEFR B2

a traditional male first name or a family name.

For teachers: a male given name of Germanic origin, or a common surname derived from the same root.

- Mr. Lambert has been teaching history at this school for twenty years.
- The historical documents were signed by a man named Lambert, though his exact role in the administration remains unclear.

## Examples

- The scientist measured the brightness in Lamberts.
- Engineers calculated the screen's brightness in Lamberts to ensure it remained visible under direct sunlight.
- While the candela per square metre is now the standard metric unit, the Lambert remains a historical reference point in early twentieth-century optical physics and lighting design.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.