Percentile

How to spell percentile

10 letters · 3 syllables

How to pronounce percentile

Say the part in capitals loudest.

What does percentile mean?

1. nounA value below which a given percentage of observations in a group falls, used to rank a score relative to others.

Percentile in a sentence

• Her test result placed her in the ninetieth percentile for the whole region.

• The doctor noted that the baby's weight sat at the fiftieth percentile for his age.

Where does percentile come from?

Language of origin: Latin

The word is a fairly modern coinage built from the older phrase 'per cent', which comes from the Latin per centum, literally meaning 'by the hundred'. To that base English added the suffix -ile, the same ending found in 'quartile' and 'decile', creating a term for one of the points that divide a ranked set of data into one hundred equal parts. It was introduced into statistics in the late nineteenth century; the English scientist Francis Galton popularised it in the 1880s while studying the distribution of human measurements. The spelling preserves the 'cent' of 'per cent' intact, which is the key to remembering it: think 'per cent' plus '-ile'. Because the term lives almost entirely in technical and educational writing, it is far less worn into everyday memory than its cousins 'percent' and 'percentage'.

How the word is built

• per (Latin per: by)
• cent (Latin centum: hundred)
• -ile (noun-forming suffix, on the model of words like quartile)