adjective
Definition: Referring to a character or symbol that is written or printed below the normal line of text.
Example: In the chemical formula, the number of atoms is often shown as a subscript.
noun
Definition: A special character or symbol that is written below and to the side of a letter or number, often used in mathematics or chemistry to indicate a specific meaning.
Example: In the chemical formula H₂O, the '2' is a subscript that shows there are two hydrogen atoms.