Back-hander is a word that is used to describe a bribe given secretly to someone in authority. It is considered unethical, illegal, and can lead to severe consequences. Therefore, it is crucial to have synonyms for this term to avoid using it in any official or personal communications. Some of the words that can be used in place of back-hander include bribery, pay-off, hush money, graft, kickback, enticement, inducement, incentive, gift, and gratuity. It is essential to note that using any of these synonyms in the context of offering a bribe is considered an offense. Instead, it is better to use them in their original meaning.