Improvidence is the habit of not looking ahead — especially with money. An improvident person spends what they have now and does not save for later, or they do not plan for trouble that a careful person would see coming. The word is formal and a little old. You will meet it in essays and older books more than in chat. Though actually, calling someone improvident is a judgement: it says they should have known better, not only that they are poor. Being poor and being improvident are not the same thing. The opposite idea is providence: care and planning for what is coming.

沒有遠慮、不知積蓄（書面語，指責人花錢或計畫太短視）