Sundial: Definition, Usage & How It Tells Time

Meaning 1：solar timekeeper (sundial)

sundial 🔊

/ˈsʌnˌdaɪəl/

An old tool that uses the shadow of the sun to tell the time.

Sundial in garden showing shadow on Roman numerals for solar timekeeping illustration

solar timekeeper 🔊

➕

/ˈsoʊlər ˈtaɪmkiːpər/

A device that indicates the time of day by measuring the position of the sun's shadow on a marked surface.

📁 Category：Culture & History 🔖 Level：Intermediate

📘 Details & Usage

📖 Root Explanation

From 'sun' + 'dial', where 'dial' derives from Latin 'dies' meaning 'day'.

💡 Mnemonic

SUN + DIAL: imagine the SUN casting a shadow on a DIAL to show the time.

📖 Example

The old stone sundial in the garden still works perfectly on sunny days. 🔊 An ancient stone sundial in a garden remains accurately functional during sunny weather.

🔗 Collocations

stone sundial – a sundial constructed from stone material

garden sundial – a sundial commonly placed in a garden setting

ancient sundial – a historical sundial from early civilizations

🔄 Synonyms

sun clock (n.) – a timekeeping instrument that uses the sun's position to indicate hours

shadow clock (n.) – a device that tells time by the movement of shadows cast by the sun

dial (n.) – a flat plate with markings, often part of a sundial, for showing time or direction

🚫 Antonyms

digital clock (n.) – an electronic clock that displays time numerically, not relying on shadows or sunlight

mechanical clock (n.) – a clock operated by gears and springs, independent of solar observation

📖 Cultural Story

Sundials originated in ancient Egypt around 1500 BCE, using obelisk shadows for timekeeping. They were crucial before mechanical clocks, symbolizing early scientific observation of solar movement.