lackadaisical
From Longman Dictionary of Contemporary Englishlackadaisicallack‧a‧dai‧si‧cal /ˌlækəˈdeɪzɪkəl◂/ adjective INTERESTEDnot showing enough interest in something or not putting enough effort into it David has a rather lackadaisical approach to his work.Examples from the Corpuslackadaisical• a lackadaisical approach to securityOrigin lackadaisical (1700-1800) lackaday expression of sadness ((17-19 centuries)), from alack the day