Longman Dictionary of Contemporary English - goodness

~ n 1 my goodness!/goodness (gracious) me! spoken used to when you are surprised or sometimes angry  (My goodness, you did buy a lot!) 2 have the goodness to do sth formal used to show extreme politeness when asking someone to do something  (Will you have the goodness to excuse me?) 3 for goodness' sake spoken used when you are annoyed or surprised  (For goodness' sake stop arguing!) 4 goodness (only) knows spoken used to emphasize that you are not sure about something or to make a statement stronger  (That bar's been closed for goodness knows how long. | Goodness knows, I tried to help him!) 5 »BEING GOOD« the quality of being good  (Claire has an essential goodness of character.) 6 »BEST PART« the best part, especially the part of food which is good for your health  (All the goodness of an egg is in the yolk.)