1. in the direction of the length of something; along the longest axis
2. over a period of time; in a way that tracks changes or developments across time
Usage: common in research and scientific contexts

Examples

• The surgeon made an incision longitudinally along the patient's leg.
• The board was cut longitudinally to create two long, narrow pieces.
• The study followed participants longitudinally over ten years to track health outcomes.
• The crack in the wall ran longitudinally from the foundation to the roof.
• Researchers examined the data longitudinally to observe trends in student performance.
• The muscle fibers are arranged longitudinally within the tissue.