stirrup cup

noun3

1. •
   A drink taken before leaving or parting company with someone.

   • Mrs. French insisted that they come into her room for a cordial, when she heard they were leaving. “You must have a stirrup cup,” Mrs. French said to Carol. — 1952
2. •
   (historical) A parting drink taken after mounting one's horse.

   • […] after the Lord Keeper, the Master, and the domestics, had drunk doch-an-dorroch, or the stirrup-cup, in the liquors adapted to their various ranks, the cavalcade resumed its progress. — 1819
3. •
   A cup from which such a drink is taken.