custos

noun3

1. •
   A monastic superior, who, under the general of his order, has the direction of all the religious houses of the same fraternity in a given district, called a custody of the order.
2. •
   (historical) In older forms of musical notation, an indication, at the end of a line of music, of the first note of the next line.
3. •
   (no longer used) A warden.

   • […] they were commytted to prison & put out of theyr offyces & the Constable of the Towre made custos of the citye. — 1530