half·heart·ed 
/ˈhæfˈhɑɚtəd, Brit ˈhɑ:fˈhɑ:təd/ adjective
/ˈhæfˈhɑɚtəd, Brit ˈhɑ:fˈhɑ:təd/ adjective [more halfhearted; most halfhearted] : feeling or showing a lack of interest or enthusiasm
▪ a half-hearted smile ▪ half-hearted applause from the audience ▪ He made a half-hearted attempt to contact them.
▪ a half-hearted smile ▪ half-hearted applause from the audience ▪ He made a half-hearted attempt to contact them.
— half·heart·ed·ly adverb
▪ smiling halfheartedly
▪ smiling halfheartedly
