longitudinal

C1 · Advanced Science Academic

adj. describing a study that follows the same people or things over many years.

adj. relating to a research method involving repeated observations of the same variables over short or long periods of time.

“The scientists started a longitudinal study to see how the children grew over twenty years.”

“A longitudinal analysis of the patient cohort revealed that lifestyle interventions in early adulthood significantly reduced the risk of chronic illness in later decades.”

C1 · Advanced Technical

adj. relating to the lines on a map that go from the North Pole to the South Pole.

adj. pertaining to longitude or the angular distance east or west of the prime meridian.

“The ship's navigator checked their longitudinal position to ensure they were on course.”

“Accurate longitudinal measurements remained a significant challenge for maritime explorers until the invention of the marine chronometer in the eighteenth century.”

C2 · Proficiency Countable noun Technology Technical

n. a long piece of a structure, like a beam in a ship, that runs from front to back.

n. a structural member, such as a stringer or girder, that runs lengthwise in a ship, aircraft, or bridge.

“The workers reinforced the longitudinals in the hull to make the boat stronger.”

“The aircraft's fuselage is supported by a series of longitudinals and frames designed to distribute aerodynamic loads evenly across the skin.”