remiss /rɪˈmɪs/

• 1. 

  ADJ If someone is remiss, they are careless about doing things that ought to be done. 懈怠的; 疏忽的 [正式] [v-link ADJ]

  例：

  I would be remiss if I did not do something about it.

  如果我对此不做点儿什么，就是懈怠。