Step 1: Understand the meaning of the word defray.
Defray means to pay or bear the cost of something.
Step 2: Examine each option:
Exit — means to go out (not related).
Spend — means to pay money (correct).
Malicious — means having evil intent (not related).
Alight — means to get down or land (not related).
Step 3: Therefore, the synonym of defray is spend.