The phrase "penny wise" typically means someone who is frugal or careful with money. The antonyms of "penny wise" include "extravagant," "reckless," "prodigal," and "lavish." Extravagant means spending more than necessary, while reckless suggests a disregard for financial responsibility. Prodigal implies wastefulness, and lavish implies overspending on luxuries. Other antonyms of "penny wise" include "improvident," "squandering," "spendthrift," and "wasteful." These words convey a different meaning from the original phrase and suggest an approach to money management that goes against being penny wise. In conclusion, there are several antonyms for "penny wise," and each word describes a different financial behavior.