The phrase "easy of belief" refers to people who are gullible or easily fooled. There are many synonyms for this phrase, including credulous, trusting, naive, and unsuspecting. Other similar concepts include being snowed, taken in, hoodwinked, bamboozled, or duped. All of these words describe a susceptibility to being tricked or deceived, often because of a lack of critical thinking or skepticism. However, it is important to note that being easy of belief does not necessarily mean that someone is foolish or unintelligent; rather, it is a vulnerability that can be exploited by unscrupulous individuals.