Prevent Purely Numeric Template Variables

Prevent, anticipate, forestall mean to deal with beforehand. Prevent implies taking advance measures against something possible or probable. To prevent is to stop something effectually by forestalling action and rendering it impossible:

To prevent the sending of a message. From middle english preventen ("anticipate"), from latin praeventus, perfect passive participle of praeveniō ("anticipate"), from prae ("before") + veniō ("come"). See examples of prevent used in a sentence.

The verb prevent means "to keep something from happening," like when you use a complicated password to prevent hackers from accessing your account. Definition of prevent verb in oxford advanced learner's dictionary.