Longitudinal

How to spell longitudinal

12 letters · 5 syllables

How to pronounce longitudinal

Say the part in capitals loudest.

What does longitudinal mean?

1. adjectiveRunning along the length of something, rather than across it.
2. adjectiveDescribing a study that observes the same subjects repeatedly over a long period of time.

Longitudinal in a sentence

• The carpenter cut a longitudinal groove down the centre of the plank.

• The longitudinal study tracked the same children from birth into adulthood.

• The bridge develops fine longitudinal cracks that follow its full span.

• Researchers favoured a longitudinal design to measure how attitudes shifted across decades.

Where does longitudinal come from?

Language of origin: Latin

This word traces back to the Latin noun longitudo, which simply meant 'length', built on the adjective longus, meaning 'long'. From longitudo came the idea of longitude, the measurement of distance along something, and by extension the imaginary lines that run the full length of the globe from pole to pole. English shaped the adjective longitudinal in the seventeenth century to describe anything arranged or measured along that lengthwise direction, as opposed to crosswise or transverse. The same longus root still lives in everyday words such as 'long', 'elongate', and 'prolong', which is a useful reminder that the trickier middle of the word is really 'longitud-' plus the ending. In modern research the word took on a further life, describing studies that follow the same subjects along a long stretch of time rather than across a single moment.

How the word is built

• longitudin- (from Latin longitudo: length)
• -al (adjective suffix)