Entropy

How to spell entropy

7 letters · 3 syllables

How to pronounce entropy

Say the part in capitals loudest.

What does entropy mean?

1. nounA measure of disorder or randomness in a system, especially the thermodynamic quantity describing energy that is no longer available to do useful work.

Entropy in a sentence

• The physics lecture explained how entropy tends to increase in a closed system.

• Engineers must account for entropy when calculating how much energy is lost as heat.

Where does entropy come from?

Language of origin: Greek

The word entropy was deliberately coined in 1865 by the German physicist Rudolf Clausius, who wanted a name for a thermodynamic quantity that measures how energy spreads out and becomes unavailable for work. He built it from Greek roots so that it would echo 'energy': he took en, meaning 'in' or 'within', and tropē, meaning 'a turning' or 'transformation', so the term literally suggests 'transformation content'. Clausius chose the spelling and sound carefully because he wanted the new word to look and feel like a sibling of the existing scientific word energy. From physics it spread into information theory in the twentieth century, where Claude Shannon used it for the amount of uncertainty in a message, and into everyday speech as a loose label for disorder and gradual decline. The same tropē root that gives us the unexpected -trop- in the middle also sits inside familiar words like 'tropic' and 'heliotrope', which is a useful clue for remembering the spelling.

How the word is built

• en- (in, within)
• trop (turning, transformation, from Greek tropē)
• -y (noun-forming suffix)