Best definition
The popular pairing between Xigbar and Demyx from the game Kingdom Hearts II. It is always changing and everyone has a specific view on how the two would act in a fancfiction. Most people believe Xigbar is a pervert while Demyx is his clueless prey so to speak. A more popular word for this pairing is XigDem and is used a lot more than the cleverly devised term Ximyx.
In this pairing it is well known to most fans that Xigbar is the SEME(dominant) and Demyx is the UKE(submissive). It is often a joke that Xigbar can use his powers to only be more of a perverted old Nobody. Another reason for people liking this is because it is known that Xigbar was the one who put Demyx up to the mission to get Sora(A.K.A Roxas)
Xigbar Fangirl: “XigDem isn’t as cool as saying Ximyx”

Demyx Fangirl: “Totally~”

– – – –

Random Fan 1: “Ximyx is NOT a ripoff of the word Zemyx!”

Random Fan 2: “YEAH IT IS!”

Random Fan 1: “IS NOT!”