What does malformed mean?
Malformed describes something that has been formed incorrectly, whether physically, grammatically, structurally, or technically. The word is especially common in computing and data processing, where malformed data or malformed code means that information does not follow the required format and may therefore be unreadable or invalid. It can also describe a body or object with an abnormal shape, a sentence with faulty structure, or a document that has been damaged or assembled improperly. The term is more precise than simply saying that something is wrong: it points specifically to a failure of formation or organization. In ordinary conversation, “malformed” often has a technical tone, while “misshapen” may be more natural for a visibly misshapen object and “incorrect” is broader when the problem concerns the content rather than its structure.
adjectiveIncorrectly formed or structured; not fitting the expected or required pattern. It can describe physical objects, written language, data, or ideas that are defective in shape, grammar, or organization.
- Incorrectly formed or structured, especially in a way that departs from an expected physical, grammatical, or structural pattern.
- Unsuccessfully formed, such as when a biological structure develops abnormally.
- Not valid or usable because it fails to meet a required format or specification, especially of data, code, or electronic communications.
"The malformed message was rejected because its structure did not follow the required format."
"The malformed document would not open in any standard word-processing program."
"The system rejected the request after detecting malformed data from the device."
What looks like a tiny formatting error can be enough to make an entire document unreadable to a computer.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does malformed come from?
The word is formed in English from the combining form “mal-” meaning “bad” or “badly” and the past participle “formed,” meaning shaped or constructed. The prefix comes through French from Latin “malus,” meaning bad or evil, while “formed” comes from Latin “formare,” meaning to shape or fashion. The same Latin bad-forming element appears in related words such as “malfunction” and “malformation.”
Related word forms
How malformed is actually used
The adjective is formal and technical in many contexts, especially computing, data processing, and document standards. In general use, it often suggests that something is visibly or obviously flawed rather than merely unconventional.
Easily confused with malformed
No distinct commonly confused word is required for this entry.