Looks like he or she is from Slavakia, so I would say a worn Roman Silver Plated Denarius...just a guess though.It is not a flattened piece of solder most likely. See the denticles around the edge? Yes, it is a silver coin. Please tell us what country this was found in, so that we can better guess. Thanks!
It did cross my mind that it might have been a contempary copy of a Mark Antony Denarius, because I to have had one.