1. the former systematic name for the chemical element seaborgium (element 106)
Usage: chemistry; obsolete

Examples

• Unnilhexium was the temporary name used for element 106 before it was officially named seaborgium.
• Scientists referred to the newly discovered element as unnilhexium until a permanent name was chosen.
• The systematic naming convention led to unnilhexium being used in early scientific papers.
• Unnilhexium is no longer used since the element received its official name in 1997.