lackadaisical /ˌlækəˈdeɪzɪkəl/ adjective2 •Showing no interest, vigor, determination, or enthusiasm."Then let those who do know it learn that you are able to bear such wounds without outward complaint. I tell you fairly that I cannot sympathize with a lackadaisical lover." — 1864 •Lazy; slothful; indolent. formsmore lackadaisical · most lackadaisical