"Ponying up" is a slang expression that typically means to provide or contribute money, often reluctantly or with a degree of resentment. Some antonyms of "ponying up" include hoarding, withholding, refusing, and abstaining. Hoarding is the act of keeping money or resources for oneself, rather than sharing it with others. Withholding involves keeping back or not giving something, often for selfish or strategic reasons. Refusing is the act of declining or rejecting an offer, while abstaining is the act of deliberately avoiding or foregoing something, such as contributing funds or resources. These antonyms highlight the different attitudes and behaviors that can arise when it comes to money and sharing resources.