ex·ergue 
(ĕksûrg′, ĕgzûrg′)
(ĕksûrg′, ĕgzûrg′)n.
A space on the reverse of a coin or medal, usually below the central design and often giving the date and place of engraving.
[French : Greek ex-, ex- + Greek ergon, work; see werg- in the Appendix of Indo-European roots.]
exerguereverse of a 1981 Italian 100 lire coin depicting the goddess Minerva holding an olive tree