verb ·Rare ·Advanced level

Definitions

Verb

1. 1
   To reverse the process of declaring; to unsay. transitive

   "The Constitution gives Congress the power to declare war; but does that include the power to undeclare it?"

2. 2
   To revoke the declaration of (a variable, namespace, etc.) so that it is no longer available. transitive

Example

More examples

"The Constitution gives Congress the power to declare war; but does that include the power to undeclare it?"

Etymology

From un- + declare.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.