Glossary of Literary Theory by Greig E. Henderson and Christopher Brown

Intentional fallacy:

A term used by William K. Wimsatt and M. C. Beardsley to describe the error of interpreting a work in terms of its author's professed intention in creating it. Unless intentions are realized and implied by the autonomous verbal structure itself, they are irrelevant and immaterial. From this point of view, biographical facts, authorial testimonies, and other data extrinsic to the text itself have no bearing on interpretation unless they pertain to concretely dramatized elements.