competency

noun5

1. •
   The ability to perform some task; competence.

   • The loan demonstrates, in regard to instrumental resources, the competency of this kingdom to the assertion of the common cause. — 1795
2. •
   An individual's capacity to understand the nature and implications of their legal rights and obligations.
3. •
   Implicit knowledge of a language’s structure.
4. •
   (no longer used) A sufficient supply of something.

   • the next day they returned unsuspected, leaving their confederates to follow, and in the interim, to convay them a competencie of all things they could […] — 1612
5. •
   (no longer used) A sustainable income.

   • Superfluity comes sooner by white hairs, but competency lives longer. — 1596