Downright means completely or utterly true or honest.
When we say that someone's words are downright ridiculous, we mean they're totally absurd and there's no truth to them. This is one common way the word "downright" is used - as an intensifier to emphasize how something is or isn't. You might also hear it in phrases like "I'm not joking, I'm telling you the truth, down to every last detail." In this case, "downright" is being used to assure someone that what's being said is honest and trustworthy.
Directed vertically; coming straight down.
Really; actually; quite
Example: He wasn’t just cool to me, he was downright rude.
