lanthanide

/ˈlænθənaɪd/

lanthanide noun: any of the 15 rare earth elements from lanthanum to lutetium in the periodic table; because their outermost orbitals are not filled, they have very similar chemistry; below them are the actinides.

Noun

lanthanide (plural lanthanides)

Any of the 15 rare earth elements from lanthanum to lutetium in the periodic table; because their outermost orbitals are not filled, they have very similar chemistry; below them are the actinides.
Any of the 14 rare earth elements from lanthanum to ytterbium (lutetium is excluded by some authors as it is a d-block rather than an f-block element).
(dated) Any of the 14 rare earth elements from cerium to lutetium (lanthanum having been excluded because it was thought to be a d-block element in the past).

Synonyms of lanthanide

Forms of lanthanide

plural	lanthanides

Origin of lanthanide

From lanthanium + -ide.

Words formed from lanthanide

Phrases with lanthanide

lanthanide contractions

Questions about lanthanide

What does lanthanide mean?: Lanthanide means any of the 15 rare earth elements from lanthanum to lutetium in the periodic table; because their outermost orbitals are not filled, they have very similar chemistry; below them are the actinides.
What part of speech is lanthanide?: Lanthanide is a noun.
How do you pronounce lanthanide?: Lanthanide is pronounced /ˈlænθənaɪd/.
What is the plural of lanthanide?: The plural of lanthanide is lanthanides.

Words near lanthanide in the dictionary

Adapted from Wiktionary: lanthanide (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

Last updated: 2026-09-02

Pronunciation audio from Wikimedia Commons, each file under its own free license: LL-Q1860 (eng)-Vealhurl-lanthanide.wav.

Cite this entry: “lanthanide.” Word.ws, https://word.ws/lanthanide. Based on Wiktionary, CC BY-SA 4.0.