A MAXIM is a short sentence that expresses a general truth or principle. It is a wise saying or guideline that provides advice or insight into life. Common sayings are often used in conversation and can be found in literature as well.' A MAXIM is a five-letter phrase that is a wise saying or guideline that provides advice or insight into life. Common sayings are often used in conversation and can be found in literature as well. They are short sentences that express a general truth or principle. Examples of common sayings include 'A stitch in time saves nine' and 'An apple a day keeps the doctor away'.