IPA: //ʌnˈθrɪfti//
KK: /ʌnˈθrɪfti/
Not careful with money; spending too much or wasting resources.
His unthrifty habits led him to financial trouble.
Unthrifty → It is formed from "un-" (meaning not) and "thrifty" (from Old Norse *þrifinn*, meaning thriving or prosperous). The word "unthrifty" means not thriving or not managing resources wisely.
Think of 'not' ('un-') being combined with 'thriving' or 'prosperous' ('thrifty') to remember that 'unthrifty' describes someone who does not manage their resources well.