| Word | Definitions | Synonyms |
|---|---|---|
| ytterbite | (noun) a mineral that is a source of rare earths; consists of silicates of iron and beryllium and cerium and yttrium and erbium | Synonyms: gadolinite |
| ytterbium | (noun) a soft silvery metallic element; a rare earth of the lanthanide series; it occurs in gadolinite and monazite and xenotime | Synonyms: atomic number 70, Yb |
| yttrium | (noun) a silvery metallic element that is common in rare-earth minerals; used in magnesium and aluminum alloys | Synonyms: atomic number 39, Y |