to prevent someone from doing something or to make someone less enthusiastic about doing something by making it difficult for that person to do it or by threatening bad results if they do it

These measures are designed to deter an enemy attack. 这些措施旨在阻止敌人的进攻。

High prices are deterring many young people from buying houses. 高昂的价格让很多年轻人对于买房望而却步。