lackadaisical
🇺🇸
/ˌlækəˈdeɪzɪkl/
🇬🇧
/ˌlækəˈdeɪzɪkl/
not really interested or enthusiastic
His lackadaisical attitude during practice made the coach upset.
練習中の彼のいい加減な態度がコーチを怒らせた。