unprocessable

Unprocessable is an adjective used to describe something that cannot be processed by a person, system, or procedure. In computing and information technology, it is commonly associated with data or requests that cannot be handled as submitted, due to errors, inconsistencies, or constraints that prevent successful processing.

One notable usage is the HTTP status code 422 Unprocessable Entity, defined in the WebDAV extension to HTTP. This status indicates that while the request's format is syntactically correct, the content is semantically invalid for the requested operation, such as missing required fields or values that violate business rules.

This status differs from 400 Bad Request, which signals a more general problem with the request's syntax or structure rather than its meaning.

In data processing and software APIs, "unprocessable" flags inputs that cannot be processed by a pipeline or validator. When a server returns such a result, clients typically adjust the input data and retry.

Outside computing, the term can describe documents, forms, or processes that cannot be executed due to technical, legal, or logistical constraints.