Problem with some english words

[CarnivorousJelly]

Rom you sneaky bugger, that's the word!

Okay, so

Definitely - means without a doubt example: "I am definitely not a boy"

Defiantly/Definately - I see "defiantly" more often, probably because it's an actual word. It means to do something with bold disobediance example "after I told him to behave himself, he defiantly ran around the room screaming bloody murder and kicked over the cake"