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Science & TechnologyGreekEnglish

Diode

/ˈdaɪəʊd/noun

A component that lets electric current pass in one direction and blocks it in the other.

The Greek roots

δίς
dís
twice, two
+
ὁδός
hodós
way, path

Literally: two ways

The story of the word

The -ode is a road. William Whewell built electrode for Faraday in 1834 out of ἤλεκτρον and ὁδός, a way, and every later part inherited the ending: diode, triode, pentode, counting electrodes rather than paths. William Henry Eccles proposed diode for the two-electrode valve in 1919. A two-way name for the most one-way device in electronics is the small joke inside the word.

How it travelled
Ancient Greek → scientific coinage → English
First recorded
1919

Same family

electrodecathodeanodeexodus

In a sentence

One diode across the relay coil stops the back-voltage from killing the transistor.

Every light-emitting diode in the room is drawing a few milliamps.

Built on the same root

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