[adjective]She seems to have enjoyed a fairly harmonious (= friendly and peaceful) relationship with all three of her children.The government is understandably reluctant to do anything which might spoil the harmonious (= friendly and peaceful) relations between the country's ethnic groups.In his later paintings he used a more harmonious (= matching well together) blend of colours.
HARMONIOUS
Meaning of HARMONIOUS in English
Cambridge English vocab. Кембриджский английский словарь. 2012