Meaning of “goodness” - Learner’s Dictionary

goodness

noun uk us /ˈɡʊdnəs/

[ U ] the quality of being good:

She believes in the goodness of human nature.
my goodness informal

something you say when you are surprised:

My goodness, he's a big baby, isn't he?
thank goodness informal

something you say when you are happy because something bad did not happen:

Thank goodness that dog didn't bite you.
for goodness sake

used when you are annoyed or when you want something to happen quickly:

For goodness sake, come in out of the rain.

(Definition of “goodness” from the Cambridge Learner’s Dictionary © Cambridge University Press)