Elaine was part of the masturbation episode and lost, which further speaks to the progressiveness of the show because a woman was portrayed as having sexuality that was outside of acceptable limits at the time (for love only, preferably in marriage). They also presented being gay as acceptable, which was quite progressive at the time where people were calling each other “gay” and the f-word as a terrible insult.
I thought the same, but an internet search says it means “late to the party”.