longitudinal

adjective

lon·​gi·​tu·​di·​nal ˌlän-jə-ˈtüd-nəl 

-ˈtyüd-,

-ˈt(y)ü-dᵊn-əl,

 British also  ˌläŋ-gə-

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

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

Recent Examples on the Web

The narrower body of the Lite means Tune has to swing the bed around 90 degrees into a longitudinal 72 x 60-in (183 x 152-cm) double. —New Atlas, 28 June 2025

Nature/Getty Images The study, led by management researcher professor Aaron Hill of the University of Florida, examined links between CEO personality traits and executive pay outcomes using a longitudinal sample of S&P 500 firms. —Alice Gibbs, MSNBC Newsweek, 19 June 2025

This homegrown hypercar can maintain a ridiculous 1.3 g’s of longitudinal acceleration through the entirety of first and second gears. —Lawrence Ulrich, Robb Report, 19 June 2025

The lens shows some longitudinal chromatic aberration (LoCA) in scenes that are typical problem areas for the effect. —PC Magazine, 22 Apr. 2025

Word History

First Known Use

15th century, in the meaning defined at sense 2

Phrases Containing longitudinal

• longitudinal wave

Rhymes for longitudinal

• altitudinal
• attitudinal
• latitudinal

Kids Definition

longitudinal

adjective

lon·​gi·​tu·​di·​nal ˌlän-jə-ˈt(y)üd-nəl 

-ᵊn-əl

1

: of or relating to length

2

: placed or running lengthwise

longitudinally

-ē

adverb

Medical Definition

longitudinal

adjective

lon·​gi·​tu·​di·​nal

ˌlän-jə-ˈt(y)üd-ᵊn-əl, -nəl, British also ˌläŋ-gə-ˈtyüd-

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

longitudinally

-ē 

adverb