Iridium and Metallic element

Iridium noun - A heavy brittle metallic element of the platinum group; used in alloys; occurs in natural alloys with platinum or osmium.

Metallic element and iridium are semantically related. In some cases you can use "Metallic element" instead a noun "Iridium".

Metallic element noun - Any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc..

Iridium and metallic element are semantically related. Sometimes you can replace term "Iridium" with "Metallic element", this terms are similar.