ruthfully
/ˈruːθfʊli/ /ˈruːθf(ə)li/adverb
1In a pitiable or lamentable fashion; piteously, dolefully, dismally. Now usually: in a wryly regretful manner, ruefully.
2Compassionately.
Origin
Middle English; earliest use found in St. Katherine. From ruthful + -ly. In later use in sense 1 probably influenced semantically by association with ruefully.