Pony up is a phrase that means to PAY or contribute money. It is derived from the phrase 'put your money where your mouth is' and is often used in gambling contexts. The two crossword solutions for the term pony up are PAY (3 letters) and ANTE (4 letters). PAY is a verb meaning to give money in exchange for goods or services, while ante is a noun meaning a stake or contribution of money put up in a game or contest.