Thriftiness is the quality of being careful with money — not spending more than you need to, using things until they are worn out, looking for the cheaper way to do something. It is the noun for the habit itself, so you talk about someone's thriftiness the way you talk about their kindness or their patience: 'her thriftiness', 'a habit of thriftiness'. The word carries approval. English has other words for spending little — 'stinginess', 'meanness' — and those are insults. Thriftiness is a virtue: it says the person is wise, not that the person is small-hearted. The line between them is who benefits. A thrifty person saves so the family has enough; a stingy person keeps money back from people who need it. Though actually, you will not hear this word often in speech. It is a slightly bookish, old-fashioned noun, the kind that appears in a written character description or an article about saving money. In real conversation people say 'she's thrifty' or 'she's good with money' and never reach for the four-syllable noun. There is also an older, mostly gone meaning where thrift meant growing and doing well — that sense now lives only in the verb 'thrive'.

節儉、節省（指「節儉這個特質」本身）