10 letters · 14 points in Scrabble
noun any element of the lanthanide series (atomic numbers 57 through 71)
originEtymology tree English lanthanium Proto-Indo-European *dʰeh₁-der. Proto-Italic *-iðos Latin -idusder. English -ide English lanthanide From lanthanium + -ide.
Etymology from Wiktionary, CC BY-SA 3.0