The term 'bind by an obligation' can be broken down into four crossword solutions: LASH, DUTY, TIE, and DEBT. LASH is a verb meaning to fasten or secure with a rope or cord. DUTY is an obligation to do something, usually as part of a job or role. TIE is a noun referring to a connection or link between two people or things. Finally, DEBT is a noun meaning a sum of money owed by one person to another. Together, these words suggest that someone is bound by an obligation to fulfill a DUTY, which is connected to a DEBT that must be paid.