Beautiful, elegant and unusual. Certainly not overused. It is the European version of Olivia, a first name. I'm not sure why it isn't used more in the US, especially since it is often a last name (in some countries) and these days many last names are used as first names. Definitely a very feminine and girly name. You need to meet an Olivera and you will know how beautiful someone with the name Olivera is, inside and out. Very memorable. Lovely!