The phrase "spend like water" implies reckless spending without any consideration for the consequences. Its antonyms, therefore, would be words that suggest the opposite behavior. Thrift, frugality, saving, conservation, economy, and austerity are all antonyms for "spend like water." Each of these words represents a different approach to money management. For example, thrift refers to the wise use of resources, while frugality suggests living with less. Saving involves putting money aside for a specific purpose, while conservation means reducing waste. Economy refers to careful spending, while austerity suggests limiting consumption to essentials. In short, if you want to avoid spending like water, you can adopt any of these antonyms to help you manage your money wisely.