The crossword solution for the term UNUSUAL PARTNER is CRUEL, which is a five-letter word. The term 'UNUSUAL PARTNER' implies an unlikely or unexpected relationship between two people or entities. This could be a romantic relationship, a business partnership, or any other type of relationship that is not typical. In this case, the term 'CRUEL' suggests that the relationship is one of conflict or hostility, which is certainly an UNUSUAL type of partnership.