longitudinal

American  

[lon-ji-tood-n-l, -tyood-] / ˌlɒn dʒɪˈtud n l, -ˈtyud- /

adjective

1. of or relating to longitude or length.

   longitudinal measurement.

2. extending in the direction of the length of a thing; running lengthwise.

   a thin, longitudinal stripe.

3. Zoology. pertaining to or extending along the long axis of the body, or the direction from front to back, or head to tail.

4. pertaining to a research design or survey in which the same subjects are observed repeatedly over a period of time.

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noun

1. a longitudinal framing member, as in the hull of a ship.

longitudinal British  

/ ˌlɒŋɡ-, ˌlɒndʒɪˈtjuːdɪnəl /

adjective

1. of or relating to longitude or length

2. placed or extended lengthways Compare transverse

3. psychol (of a study of behaviour) carried on over a protracted period of time

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Other Word Forms

• longitudinally adverb

Etymology

Origin of longitudinal

1535–45; < Latin longitūdin- (stem of longitūdō; longitude ) + -al ¹

Example Sentences

To study these patterns over time, the researchers analyzed longitudinal data from the national Health and Retirement Study.

From Science Daily

Then, I used the longitudinal feature of the CPS to follow up with those same individuals when they were interviewed one year later.

From MarketWatch

A longitudinal study involves repeatedly collecting data from the same group over an extended period, tracking changes and trends over a period of time.

From Science Daily

Lewis, the Measure of America director, pointed to a longitudinal study of young people in similar situations.

From Los Angeles Times

A prospective longitudinal study, he said, would help clarify how mental health and meditation interact over time.

From Science Daily

Related Words

• lengthwise
• long
• long-term