pyx

1. A small, usually round container used to hold the consecrated bread of the Eucharist, especially used to bring communion to the sick, or others who are unable to attend Mass.
2. A box used in the British mint as a place of deposit for certain sample coins taken for a trial of the weight and fineness of metal before it is sent from the mint.
3. The box in which the compass is suspended; the binnacle.
4. Pyxis.

verb

To test (sample coins) for the weight and fineness of metal before they are sent from the mint.