arranged in or extending along a straight or nearly straight line: linear arrangements | linear in shape | linear movement.
consisting of or predominantly formed using lines or outlines: simple linear designs.
involving one dimension only: linear elasticity.
Mathematics able to be represented by a straight line on a graph; involving or exhibiting directly proportional change in two related quantities: linear functions | linear relationship.
If I refer to twenty linear miles, do those twenty miles need to be all in one straight line? Or does twenty linear miles simply mean twenty miles of length, whatever the route, as opposed to twenty square miles?
If linear describes the miles, collectively, it should all be in one straight line, but linear could also refer to each individual mile, like a linear foot.
The phrase may be ambiguous, but what's the primary interpretation?
Edit after first close vote:
If a twenty-mile long line is not straight, can you call it twenty linear miles?