A2 adjective /ˈkeər.ləs/
Careless
不注意な; 無頓着な; 不注意な; おおざっぱな;
Meaning
not giving sufficient attention or thought to avoiding harm or errors; negligent; inattentive
Example
His careless driving caused a serious accident on the highway.
彼の不注意な運転が高速道路で深刻な事故を引き起こしました。