What does inverse mean?
Inverse is chiefly used to describe something that is reversed, opposite in order or direction, or arranged so that it undoes another operation or quantity. In everyday contexts, it can characterize a reversed sequence, an opposite result, or a movement in the opposite direction. Mathematics gives the word its most precise application: an inverse function reverses a function's action, while an additive or multiplicative inverse restores a number to zero or one when combined with the original. As a noun, an inverse is the operation, number, or function that provides this undoing relationship. The verb inverse is comparatively uncommon and formal, though it appears in technical and business writing. The term conveys precision and reversal rather than simple opposition: an inverse is not merely different, but specifically turned back or arranged to counteract what precedes it.
Reversed in order, direction, or effect; in mathematics, opposite to a quantity or operation in a way that undoes or counteracts it.
"Multiplying the matrix by its inverse produces the identity matrix."
The mathematical sense is precise, while the general sense is formal and can imply a complete reversal rather than merely a difference.
An operation, quantity, or function that undoes or counteracts another of the same kind.
"The inverse of the function f(x) = 2x is f⁻¹(x) = x/2."
The noun is standard in mathematical, scientific, and technical writing.
To reverse or invert the order, direction, or arrangement of something.
"The command inverses the order of the rows."
This use is less common than the adjective and noun; invert or reverse is often preferred in ordinary prose.
The plural is used for separate inverse values, operations, or functions.
"The inverses of these matrices are easy to calculate."
In mathematics, an inverse does more than point the other way—it undoes the original operation.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does inverse come from?
The word entered English in the early 17th century in a form influenced by Latin inversus, the past participle of invertere, meaning “to turn upside down.” Latin invertere combines in- (“into” or “in”) with vertere (“to turn”). Inversion, invert, conversion, version, and diverse belong to the wider family of English words associated with this Latin root.
Related word forms
How inverse is actually used
The word is common in mathematical and scientific writing and is also used in formal contexts such as logic, finance, and statistics. As a verb, it is comparatively uncommon; invert or reverse is often more natural. British and American speakers differ in the pronunciation of the final syllable.
Easily confused with inverse
A reciprocal is a quantity obtained by taking the reciprocal of a number, whereas an inverse more broadly can be an operation or function that undoes another.
Reverse generally means turned or ordered backward, while an inverse may specifically be constructed to undo a mathematical operation or function.