indium

UK: /ˈɪndɪəm/ US: (in′dē əm)

WordReference Random House Unabridged Dictionary of American English © 2025

in•di•um  (in′dē əm), n. [Chem.]

1. Chemistry a rare metallic element, soft, white, malleable, and easily fusible, found combined in various ore minerals, esp. sphalerite: so called from the two indigo-blue lines in its spectrum. Symbol: In;
   at. wt.: 114.82;
   at. no.: 49;
   sp. gr.: 7.3 at 20°C.

• Neo-Latin, equivalent. to ind(icum) indigo + -ium -ium
• 1860–65

Collins Concise English Dictionary © HarperCollins Publishers::

indium / ˈɪndɪəm/ noun

1. a rare soft silvery metallic element associated with zinc ores: used in alloys, electronics, and electroplating. Symbol: In; atomic no: 49; atomic wt: 114.82; valency: 1, 2, or 3; relative density: 7.31; melting pt: 156.63°C; boiling pt: 2073°C

Etymology: 19th Century: New Latin, from indigo + -ium