longitudinal

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

ADJECTIVE

over a protracted period of time; running lengthwise

Synonyms

STRONGEST

lengthwise long long-term

STRONG

continuing endlong long-run protensive

WEAK

continued drawn-out elongated extensive linear longstanding overall prolonged protracted

Antonyms

STRONGEST

immediate short-term

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

A 2026 longitudinal study in the Journal of Public Health reached a similar conclusion.

From The Wall Street Journal • Mar. 27, 2026

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 • Dec. 18, 2025

Marc was accepted into AllFTD, a longitudinal study that is the largest ever conducted for this disease.

From Los Angeles Times • Sep. 7, 2025

And, given that botox only lasts three to six months, any longitudinal study would have to ensure participants are going for regular top-ups.

From BBC • Aug. 23, 2025

Both transverse and longitudinal waves cause a displacement of something: air molecules, for example, or the surface of the ocean.

From "Understanding Basic Music Theory" by Catherine Schmidt-Jones and Russel Jones