contestation. noun. Dispute; the act of contesting.

This word pretty much goes right in the face of the "if you can say something with a simpler word, do that instead" rule. What can I say, it just sounds really, really cool. So yeah, it pretty much means exactly what it sounds like: rather than an actual contest which is the actual competition or whatever, contestation is the act of competing or disputing (or, the thing being disputed). It'll make more sense in the examples below (I hope):

A violent contestation grew between those who supported human modification and those who were against it.

The legendary One Piece treasure became a powerful source of contestation.

This is my word... and as such, it is beyond contestation.

That last example is my favourite way to use it (and yes, it's another A Knight's Tale reference). So really, if you need to have a really strong, authoritative way to say "argument" or "dispute" - especially for maybe a powerful/royal figure's speech - then contestation may be a good choice.

(noun root: contest)