ATOMIC NUMBER 77(noun)Did you mean?RhymesAlso try..numberedatomicallyDefinitions There is 1 meaning of the phrase Atomic Number 77. Atomic Number 77 - as a noun A heavy brittle metallic element of the platinum group; used in alloys; occurs in natural alloys with platinum or osmium Synonyms (Exact Relations)iriridium10A-Z Proximitiesatoll5atolls6atom6atom-bombatomic10 Atomic Number 77 atomical12atomically17atomicities15atomicity16atomics11