it's an extremely mild expletive. And only in certain parts of the country. Rare now.

"Ruddy" literally means red-coloured, ie. "a ruddy face" (perhaps from working, from the sun, or being generally healthy). As a soft swear word, "ruddy" is used in place of "bloody". Or maybe I should say "was used", as it's very rare to hear this nowadays.

The dictionary gives a slang meaning of ''confounded" and "darned," but in my entire life I have never heard it used in that way. The only meaning I'm familiar with is "having a healthy, reddish color," as in one's complexion.

Only amongst the 60+ crowd!

Just to update, I used it today at brunch and people had no idea what I was talking about. Be advised, use with caution in America.