Definition of Rhenium 1. A rare heavy polyvalent metallic element that resembles manganese chemically and is used in some alloys; is obtained as a by-product in refining molybdenum Noun Synonyms for word "rhenium" Semanticaly linked words with "rhenium" Hyponims for word "rhenium" etymology organorhenium etymology radiorhenium etymology renium etymologically related Rhenish etymologically related rhenate etymological origin of Rhenus [Latin] is derived from eka-rhenium is derived from rhenic is derived from rhenium dioxide is derived from rhenium heptaoxide is derived from rhenium heptaselenide is derived from rhenium heptasulfide is derived from rhenium heptasulphide is derived from rhenium trioxide