The term 'underhanded schemer' can be summed up as a person who is sneaky and deceitful in their actions. A synonym for this term is 'SNEAK, ' which is a five-letter word. This type of person often uses cunning and manipulative tactics to achieve their goals, often at the expense of others. They may also use dishonesty and deception to get what they want. Such people are often seen as untrustworthy and dangerous, as they are willing to do whatever it takes to get ahead.