tighten one's belt

tighten one's belt (to spend less money) — затянуть пояс, потуже затянуть пояса, начать экономить; начать жить скромнее

Example 1: After Dad lost his job, we really had to tighten our belts for a while.

Hence belt-tightening (reduction of expenses) — сокращение расходов, режим экономии

Example: When worldwide demand for software decreased, Microsoft had to do some belt-tightening.

Related vocabulary:
[on the cheap]
[on a shoestring]
[for a song]
[dirt cheap]