This is a very small coin. Will not show a weight on my scale, and is very thin.
Diameter 15.18 to 15.7 mm. Looks to be silver. Like the last pictures.
It is indeed a Hungarian Denar of Wladislaus II who ruled from 1490 to 1516. Though Hungarian Denars were the first European coins with a date in numerals on it, yours seems to be still without a date. Thus the reign is as close as you can get, ... unless you have a Huzsar catalogue of Hungarian coins and find a match for your variety. You can also try narrowing the time range by finding a match here http://www.mcsearch.info/search.html?search=similar%3A302217#1
I collect coins and tokens which circulated in Africa from 18th century to 2000. I sell about 7000 illustrated world coins from http://www.avscoins.com.