lingeringly       
adverb uk/ˈlɪŋ.ɡər.ɪŋ.li/ us/ˈlɪŋ.ɡɚ.ɪŋ.li/
 持续地,长时间地
in a way that lasts a long time
  She kissed him slowly and lingeringly. 她慢慢地、缠绵地吻着他。 
 He gazed softly into her eyes, then pulled away with a sigh, releasing her hands lingeringly. 他温柔地凝视着她的眼睛,然后叹了一口气拉开了距离,依依不舍地放开她的手。 
 See: lingering
 - More examples
 - She sang the refrain very low, very lingeringly
 - He died, lingeringly, of cancer.
 - I mused lingeringly on everything that had happened that day.