- The definition of lackadaisical is someone lacking spirit or interest.
An example of someone who would be described as lackadaisical is a person who makes a disinterested and half-hearted attempt at his schoolwork.
Origin of lackadaisical; from lackadaisy, altered (infl. by daisy) ; from lackaday
Origin of lackadaisicalFrom lackadaisy, alteration of lackaday.
(comparative more lackadaisical, superlative most lackadaisical)
From the archaic interjection lackaday, lackadaisy.