yttrium

UK: /ˈɪtrɪəm/ US: /ˈɪtriəm/ ,(i′trē əm)

WordReference Random House Learner's Dictionary of American English © 2025

yt•tri•um /ˈɪtriəm/   n. [uncountable]

1. Chemistry a rare metallic element.

WordReference Random House Unabridged Dictionary of American English © 2025

yt•tri•um  (i′trē əm), n. [Chem.]

1. Chemistry a rare trivalent metallic element, found in gadolinite and other minerals. Symbol: Y;
   at. wt.: 88.905;
   at. no.: 39;
   sp. gr.: 4.47. Cf. rare-earth element. 

• Neo-Latin, named after Ytterby. See ytterbia, -ium
• 1815–25

yt′tric, adj. 

Collins Concise English Dictionary © HarperCollins Publishers::

yttrium / ˈɪtrɪəm/ noun

1. a silvery metallic element occurring in monazite and gadolinite and used in various alloys, in lasers, and as a catalyst. Symbol: Y; atomic no: 39; atomic wt: 88.90585; valency: 3; relative density: 4.469; melting pt: 1522°C; boiling pt: 3338°C

Etymology: 19th Century: New Latin; see ytterbia