The term 'sex up' can be defined as making something more exciting or attractive. This can be done in a variety of ways, such as by adding erotic elements or by making it more lively. The two crossword solutions for this term are 'eroticize' (9 letters) and 'LIVEN' (5 letters). 'Eroticize' means to make something more sexually stimulating or appealing, while 'LIVEN' means to make something more active, energetic, or exciting. Therefore, these two words can be used to describe the process of sexing up something.