miserly
Extremely stingy and unwilling to spend money, even reasonably.
Miserly means extremely unwilling to spend money, even when spending would be reasonable or kind. A miserly person hoards their money and refuses to part with it, even for things they need or to help others.
A miserly boss might refuse to replace broken equipment to save a few dollars. A miserly neighbor might keep their heat turned low all winter to avoid the electric bill, shivering under blankets instead. The key difference between being miserly and being frugal or thrifty is that frugal people spend wisely and carefully, while miserly people barely spend at all.
Charles Dickens created literature's most famous miser in Ebenezer Scrooge, whose miserly ways made him friendless and bitter. Being careful with money shows responsibility, but being miserly means letting the fear of spending control your life. Someone described as miserly doesn't just skip luxuries: they deny themselves and others even basic comforts and kindnesses that money could provide.