The word "defrays" means to pay or settle the cost of something. Its antonyms would be words that mean the opposite, such as "owe" or "accumulate." If someone isn't defraying their expenses, they might be accruing debt, or falling into arrears. Other antonyms could include "neglect" or "ignore," as not paying for something could imply a lack of concern or responsibility towards it. In many cases, the opposite of "defrays" will depend on the context in which it is used, as well as the specific connotations surrounding the transaction or payment being discussed.