longitudinal
Used in academic, technical, or formal contexts to describe something that extends along the length or over time, such as a longitudinal study or a cross-section.
This study conducted an analysis using longitudinal data.
We track long-term changes through a longitudinal survey.
longitudinal study
longitudinal data
Formed from 縦断 (じゅうだん, 'running lengthwise') + the adjectival suffix 的 (てき, '-like, -al').