lackadaisical — ONAD

lackadaisical /ˌlakəˈdāzək(ə)l, ˌlækəˈdeɪzək(ə)l

▸ adjective lacking enthusiasm and determination; carelessly lazy:

a lackadaisical defense left the Spurs adrift in the second half.

– DERIVATIVES
lackadaisically /ˌlakəˈdāzik(ə)lē, ˌlækəˈdeɪzɪk(ə)li

/ adverb,lackadaisicalness

– ORIGIN mid 18th century (also in the sense ‘feebly sentimental’): from lackaday or its obsolete extended form lackadaisy.