just in general, I find some of onelook's "quick definitions" to be suspect because they use only sources which are free of copyright protection. one of their "quick" sources is the 1913 Webster's, which can be badly outdated.

of course, this answers none of your questions about this specific instance.

the phrase 'ante up' comes from poker, I believe, where it means pay up what you owe to get into the next hand (pot).