Os and Shoulder blade

Os noun - A hard brittle blue-grey or blue-black metallic element that is one of the platinum metals; the heaviest metal known.

Shoulder blade and os are semantically related. In some cases you can replace phrase "Shoulder blade" with "Os", this terms are similar.

Shoulder blade noun - Either of two flat triangular bones one on each side of the shoulder in human beings.

Os and shoulder blade are semantically related. Sometimes you can use "Os" instead a noun phrase "Shoulder blade".