Webster’s Revised Unabridged Dictionary · 1913
Prerequisite
Pre·req′ui·site (prē·rĕk′wĭ·zĭt), a. Previously required; necessary as a preliminary to any proposed effect or end; as, prerequisite conditions of success.
Pre·req′ui·site, n. Something previously required, or necessary to an end or effect proposed.
The necessary prerequisites of freedom. Goldsmith.