adjective

longitudinal

lahn-juh-TOO-duh-nul/ˌlɑːndʒəˈtuːdənl/

Running along a subject's length rather than across it.

The log's longitudinal split follows its grain from end to end.

A long wooden log split along its full length reveals continuous grain from end to end, lengthwise direction clear, no labels.

Etymology

longLatinlong

+itudinLatinstate or quality

+alLatinrelating to

The pieces mean “relating to length,” and the underlying noun also meant “long duration.” This connects lengthwise orientation in space with measurement along a span of time.

In context

Your Discovery Science0:26

the longitudinal threads I call the warp and the threads running across I call the weft

How Weaving Pioneered Machine Programming! - Impossible Engineering

More examples

Make a longitudinal cut to split the cucumber into two long halves.
The diagram shows a longitudinal section of the root.
Longitudinal grooves run from the handle to the tip.

Forms

longitudinally adverb — Along the length rather than across.

Similar words

lengthwise: Expresses the same direction in everyday rather than technical language.
axial: Follows a central axis, not necessarily an object's length.