Duty-bound is a term used to describe someone who is obligated to fulfill certain responsibilities or obligations. It is often used in the context of a job or profession, where an individual is expected to adhere to certain standards and fulfill their duties. Taxable and OBLIGED are two words that can be used to describe someone who is duty-bound. Taxable refers to something that is subject to taxation, while OBLIGED means to be required to do something. Therefore, someone who is duty-bound is required to fulfill their obligations and may also be subject to taxation.