From Longman Dictionary of Contemporary Englishbe in good heartbe in good heartformalHAPPY to feel happy and confident The team are in good heart and ready for the season’s matches. → heart
Examples from the Corpus
be in good heart• With the prospect of William and Harry joining them for a holiday afterwards, Diana was in good heart.• The gelding show-ed he was in good heart this week by winning at Edinburgh on Thursday.• Far from bumping along on the bottom, desperate for money, it is in good heart.• I can see the land is in good heart, and I remember enough to know the extent of the estates. 