# Hartley

/ˈhɑɹtɫi/ (US)

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

## Senses

### 1. a surname

noun · CEFR C2 · Formal

a common last name for people in English-speaking countries.

For teachers: a habitational surname derived from Old English, originally referring to a 'stag wood' or 'deer meadow'.

- The novelist L.P. Hartley is famous for writing 'The Go-Between'.
- The archival records indicate that the Hartley family held significant land in the northern counties during the seventeenth century.

Usage: Used as a proper noun for individuals or families.

### 2. a place name

noun · CEFR C2 · Formal

the name of several towns and villages in England, the US, and Australia.

For teachers: a toponym used for various settlements, most notably several villages in Kent, Cumbria, and Northumberland.

- They decided to stop for lunch in the small village of Hartley.
- Hartley remains a quiet residential parish, though its proximity to the railway has led to recent suburban development.

Usage: Used as a proper noun for geographic locations.

### 3. unit of information

noun · CEFR C2 · Technical

a technical unit used to measure information, equal to one decimal digit.

For teachers: a logarithmic unit of information or entropy, based on decadic logarithms rather than the binary bits used in computing.

- The scientist measured the data transfer in hartleys instead of bits.
- In information theory, one hartley represents the information content of an event with a probability of one-tenth.

Usage: Usually written with a lowercase 'h' when referring to the unit, but capitalized as 'Hart' for the symbol.

## Examples

- The system measures data transfer in hartleys.
- In early information theory, the hartley was used alongside the bit to quantify the capacity of communication channels.
- While the bit remains the standard unit in modern computing, the hartley provides a useful base-10 alternative for specific logarithmic calculations in classical information theory.

---

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.