What does subscript mean?
A subscript is a smaller character or symbol placed below and usually slightly to the right of another character. It is widely used in mathematics to distinguish indexed values, as in a₁ and a₂, and in chemistry to indicate the number of atoms of an element, as in H₂O. The term also applies to a small mark or inscription written beneath a main text or signature. In these uses, a subscript contrasts with a superscript, which is positioned above the baseline. The word comes from Latin sub-, meaning “under,” and script, meaning “written.” Subscripts are valuable because they add precise information without replacing the main symbol or expression. The same basic principle appears in typography and formal documentation, where smaller subordinate characters clarify relationships that would otherwise be ambiguous.
A smaller character or symbol placed below and usually to the right of another character, especially in mathematics, chemistry, or typography.
"The equation contains a subscript beneath the letter x."
The plural is subscripts. In scientific notation, the term is conventionally hyphenated when attributive: subscript notation.
To write or mark something below a line, signature, or other text.
"The witness subscripted the statement with her initials."
This use is formal and particularly associated with legal, academic, or documentary contexts.
Used when referring to more than one smaller character or symbol placed beneath a main character or expression.
"The two subscripts identify the row and column in the formula."
Without subscripts, H₂O would look like H2O and chemical formulas would lose much of their precision.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does subscript come from?
The word entered English through Latin, combining sub- (“under”) with scribere (“to write”), with the noun and verb forms developing in English during the early 17th century. Its earliest scientific uses referred to writing below another line or character. The same Latin root appears in related words such as script, prescribe, and describe, all of which involve writing.
Related word forms
How subscript is actually used
In technical and mathematical contexts, the term is usually used of a character or notation placed below the baseline. As a verb, it is formal and less common in everyday speech.
Easily confused with subscript
A subscript appears below the baseline, whereas a superscript appears above it.