- holmium oxide
- An oxide of holmium.
- A genus of trilobites of the family members Olenidæ and described as possessing 10 free portions and a tiny unsegmented pygidium. It happens within the Lower Cambrian rooks.
- In chem., one of the rare earths, found with yttria in gadolinite, and supposed to be the oxid of a definite element, holmium: but it might an as however unseparated combination.