Rectilinear (adjective)

Moving or extending in a straight line or direction.

Origin:

From latin rectus 'right' and linearis 'of or pertaining to a line'.

Examples:

1. The rectilinear path of the satellite across the sky was clearly visible.
2. A rectilinear design was chosen for the building's facade.
3. The city's streets were laid out in rectilinear pattern.
4. The arrow flew in a rectilinear trajectory.
5. The river's flow was rectilinear and rapid.