If you do something outright, you do it in a wholehearted, unrestricted way. If you declare outright that you’re never eating another cupcake, that’s the end of that. If you eat one anyway, you told an outright lie.
If an event is cancelled outright, there's no question about it being rescheduled, and if you buy a new car outright, you pay for it all at once, instead of making monthly payments. Outright means direct and immediate — whether it's an adverb or an adjective: "The child's outright refusal to put on his shoes exasperated his babysitter." It can also mean “right away.” If you step on a slug, you’ll probably kill it outright. Ew.