prerequisite

adj

1. (not-comparable)Required as a prior condition of something else; necessary or indispensable.

   “The prerequisite warm-up to the match was ignored.”

   “A good command of Spanish is prerequisite for enrolling in this course.”

noun

1. Something that is required as necessary or indispensable, or as a prior condition of something else.

   “A degree is a prerequisite for entry into this profession.”

   “Only a full-scale analysis of the origin and development of our sensations and ideas can provide this knowledge; so Hartley's associationist psychology becomes the prerequisite for moral knowledge.”

   “If you examine the prerequisites list, you will notice it does not include bootstrapper packages for the Office 2003 PIAs.”

2. A course or topic that must be completed before another course or topic can be started.

   “Algebra is typically a prerequisite for physics.”