noun
iridium
ih-RIHD-ee-uhm
noun
1
A hard, brittle, silvery-white metallic element (atomic number 77) in the platinum group, the most corrosion-resistant metal known.
"Iridium is so dense and unreactive that it is used to make the tips of high-end fountain pens."
"A thin layer of iridium found in rock worldwide is one of the key clues linking an asteroid impact to the extinction of the dinosaurs."
2
A single atom of this element.
"The compound contains one iridium atom bonded to several carbon monoxide molecules."
How to Use Iridium
Learner’s notesIn plain EnglishOne of the toughest, most corrosion-proof metals on the periodic table, often paired with platinum.
Common pairings
iridium alloy
iridium layer
iridium-tipped
Word Forms
iridiums plural
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_____ is so dense and unreactive that it is used to make the tips of high-end fountain pens.
Etymology
Named from Latin iris ("rainbow"), because many of its salts and compounds show a striking range of colours.