Angstrom unit and Metric linear unit

Angstrom unit noun - A metric unit of length equal to one ten billionth of a meter (or 0.0001 micron); used to specify wavelengths of electromagnetic radiation.

Metric linear unit and angstrom unit are semantically related. In some cases you can use "Metric linear unit" instead a noun phrase "Angstrom unit".

Metric linear unit noun - A linear unit of distance in metric terms.

Angstrom unit and metric linear unit are semantically related. Sometimes you can replace phrase "Angstrom unit" with "Metric linear unit", this phrases are similar.