Meaning
Lithium oxide, Li₂O, used in the manufacture of ceramics and glass.
Etymology
Origin: Ancient Greek
Borrowed from Ancient Greek λίθος (líthos, “a stone”), apparently because it is found only in minerals; discovered 1817 by Johan August Arfwedson.
NYT Puzzle Appearances
No published puzzle dates on file for this word yet. It is part of the official NYT Spelling Bee word list for 2019, 2020, 2021, 2022, 2023, 2024, 2025, 2026.