Cupel and Twosome

Cupel noun - A small porous bowl made of bone ash used in assaying to separate precious metals from e.g. lead.

Twosome and cupel are semantically related. In some cases you can use "Twosome" instead a noun "Cupel".

Twosome noun - Two things of the same or similar kind that match or are considered together.

Cupel and twosome are semantically related. Sometimes you can replace term "Cupel" with "Twosome", this nouns are similar.