unthrift
/ˈʌnθrɪft/Definitions
1. noun
A lack of thriftiness or a state of being wasteful; a person who is wasteful or profligate
“The family’s unthrift had led to a significant decrease in their savings over the years.”
2. verb
To spend or use money or resources in a wasteful or extravagant manner
“He unthriftily spent his inheritance on lavish parties and expensive gifts.”