goody-good
/ˈɡʊdɪˌɡʊd/depreciative
adjective
= goody-goody.
noun
1That which is ostentatiously or sanctimoniously virtuous or correct; that which is ‘goody-good’.
2= goody-goody.
Origin
Mid 19th century. From goody + good. Compare earlier goody-goody.