1. Healthy, feeling well.
2. Satisfactory, okay
, a good outcome. Used to describe a situation that's been sorted out, or turned out okay.
May be derived from the fact that is rains so much in the UK that rain is just a normal fact of life.
1. "I see you're really sick
with the flu. Please, get some rest, and I'll bring you some chicken soup. Soon, you'll be right as rain."
2. "She had lots of challenges in school. But, she studied really hard so by graduation everything was right as rain."