The Oxford Thesaurus An A-Z Dictionary of Synonyms - lackadaisicaladj.

1) lethargic, languorous, languid, listless, lazy, sluggish, spiritless, idle, indolent, inactive, slothful, fain‚ant: She's much too lackadaisical to go out and get a job. 2) unenthusiastic, dull, apathetic, insouciant, uncaring, unconcerned, indifferent, blas‚, cold, cool, lukewarm, tepid, unexcited, phlegmatic, unemotional, unexcitable, uninterested, unimpressed, uninspired, unmoved, pococurante: How can you explain the government's lackadaisical attitude towards the greenhouse effect?