Algorithm

How to spell algorithm

9 letters · 4 syllables

How to pronounce algorithm

Say the part in capitals loudest.

What does algorithm mean?

1. nounA precise step-by-step set of rules or instructions for solving a problem or performing a computation.

Algorithm in a sentence

• The search engine changed its ranking algorithm overnight.

• Engineers spent months refining the sorting algorithm for speed.

Where does algorithm come from?

Language of origin: Arabic

The word traces back to a person, not a thing: Muhammad ibn Musa al-Khwarizmi, a ninth-century scholar working in Baghdad whose surname signalled that his family came from Khwarezm, a region in Central Asia. His treatises introduced the Hindu-Arabic decimal system to the wider world, and his name was Latinised as 'algorismus', which in medieval English became 'algorism', meaning the art of calculating with those new numerals. For centuries the word kept that arithmetical sense and was spelled without the final 'th'; the modern shape 'algorithm' arose when scholars muddled the ending together with the Greek word arithmos, meaning 'number'. That blending is exactly why the spelling trap sits at the end: the unexpected '-rithm' echoes 'rhythm' rather than anything to do with a name. Only in the twentieth century, with the rise of computing, did 'algorithm' settle into its current meaning of a precise step-by-step procedure for solving a problem.

How the word is built

• algor- (from the Latinised name al-Khwarizmi, via 'algorism')
• -ithm (ending reshaped under the influence of Greek arithmos 'number')