Exergue
Exergue , noun
[French, from Greek {not transcribed} out + {not transcribed} work; lit., out work, i. e., accessory work. See Work.]
(Numismatics) The small space beneath the base line of a subject engraved on a coin or medal. It usually contains the date, place, engraver's name, etc., or other subsidiary matter. — Fairholt