“required”

A requirement for something; something needed.

To do as a requirement; indicates that the sentence subject is required as an imperative or directive to execute the sentence predicate, with failure to do so resulting in a failure or negative consequence.

To give money or other compensation to in exchange for goods or services.

To recall from one's memory; to have an image in one's memory.

To incur a charge of; to require payment of a (specified) price.

Necessary; being required.

Only a small amount of something is usually required to produce a great effect.

To make a contribution; help in a small way; especially, to pay for a part of something.

To prepare; to establish the basis or required conditions.