tighten ones belt

(a) kemerleri sıkmak: müşkülât/sıkıntı/zaruret ve sefalete sabırla katlanmak, (b) masrafları kısmak,
tutumlu davranmak.
They were urged to tighten their belts for the war effort. In a period of unemployment a lot of people must learn to tighten their belts.