lon·​gi·​tu·​di·​nal | \ ˌlän-jə-ˈtüd-nəl How to pronounce longitudinal (audio) , -ˈtyüd-, -ˈt(y)ü-dᵊn-əl, British also ˌläŋ-gə- \

Definition of longitudinal

1 : placed or running lengthwise The insect's back is black with yellow longitudinal stripes.
2 : of or relating to length or the lengthwise dimension the longitudinal extent of the building
3 : involving the repeated observation or examination of a set of subjects over time with respect to one or more study variables a longitudinal study of juvenile offenders over a period of five years

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Other Words from longitudinal

longitudinally adverb

Examples of longitudinal in a Sentence

The insect's body is black with yellow longitudinal stripes. calculating the longitudinal position of a ship a longitudinal study of career aspirations among girls from 5 to 17
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Recent Examples on the Web The researchers gathered two longitudinal samples of a diverse group of Icelandic youngsters to test whether long-term personality changes can influence our career outcomes over and above things like our ability. Pavel Krapivin, Forbes, "How Personality Changes Impact Our Career," 4 May 2021 Adding an upper control arm reduces friction, keeps longitudinal forces from affecting the dampers, stabilizes the tire under cornering pressure, and helps minimize brake dive without having to stiffen the spring rates. Tony Quiroga, Car and Driver, "2022 Porsche 911 GT3 Leaves Us Breathless," 20 Apr. 2021 Young people not protected by prior infection, study suggests Antibodies produced by a COVID-19 infection do not completely protect young people against reinfection, according to a longitudinal study of more than 3,000 healthy U.S. Marines. Julie Washington, cleveland, "Less than 1% of vaccinated people getting COVID-19; dogs trained to sniff out virus: Coronavirus update for Monday, April 19," 19 Apr. 2021 Other research has found that SCT does have some longitudinal stability. Rebecca Sohn, STAT, "On a limb: Despite resistance, a group of researchers is investigating the possibility of a new mental health disorder," 14 Apr. 2021 In the narrower longitudinal grooves closer to the sidewalls of the tyre, just one of these white columns was visible. Laurie Winkless, Forbes, "Scientists Unveil What Happens When Tyres Slide On Wet Roads," 17 Mar. 2021 Also noteworthy is that this dramatic gain in longitudinal grip has occurred with almost no improvement in lateral grip. Annie White, Car and Driver, "GM's Big SUVs Can Stop Shorter Than a Mazda 3," 29 Dec. 2020 Those troubling trends are borne out in longitudinal studies too. Your Fat Friend, SELF, "How You Might Be Benefiting From Thinness—Even If You Don’t Feel ‘Thin’," 9 Mar. 2021 The disparity in how ED doctors and oncologists typically use CT imaging—emergent and unplanned for immediate decisioning versus longitudinal monitoring at regular intervals—mirror the spectrum of complexity involved in scanning a single patient. Mohan Giridharadas & Sanjeev Agrawal, Forbes, "Improving Turnaround Time For CT Scans - A Study In Balanced Processes," 26 Feb. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'longitudinal.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of longitudinal

15th century, in the meaning defined at sense 2

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Time Traveler for longitudinal

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The first known use of longitudinal was in the 15th century

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Last Updated

13 May 2021

Cite this Entry

“Longitudinal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/longitudinal. Accessed 14 May. 2021.

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More Definitions for longitudinal



English Language Learners Definition of longitudinal

: placed or going along the long side of something
: of or relating to longitude
: done by observing or examining a group of people or things over time to study how one or two particular things about them change


lon·​gi·​tu·​di·​nal | \ ˌlän-jə-ˈtü-dᵊn-əl How to pronounce longitudinal (audio) , -ˈtyü- \

Kids Definition of longitudinal

: placed or running lengthwise longitudinal stripes

Other Words from longitudinal

longitudinally adverb


lon·​gi·​tu·​di·​nal | \ ˌlän-jə-ˈt(y)üd-ᵊn-əl, -nəl, British also ˌläŋ-gə-ˈtyüd- \

Medical Definition of longitudinal

1 : of, relating to, or occurring in the lengthwise dimension a longitudinal bone fracture
2 : extending along or relating to the anteroposterior axis of a body or part a trypanosome which reproduces by longitudinal fission
3 : involving the repeated observation or examination of a set of subjects over time with respect to one or more study variables (as general health, the state of a disease, or mortality) a longitudinal study of heart transplant recipients over a five-year period

Other Words from longitudinal

longitudinally \ -​ē How to pronounce longitudinal (audio) \ adverb

More from Merriam-Webster on longitudinal

Nglish: Translation of longitudinal for Spanish Speakers

Britannica English: Translation of longitudinal for Arabic Speakers

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