We don't have synonyms for play-party yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are play party.
(n) :
Alternative form of play party (“social gathering with singing and dancing games”). [(US, chiefly historical) A social gathering at which singing and dancing games are played, frequently held in the 19th and early 20th centuries in the American South and Midwest.]
(n) :
Alternative form of play party (“social gathering with singing and dancing games”). [(US, chiefly historical) A social gathering at which singing and dancing games are played, frequently held in the 19th and early 20th centuries in the American South and Midwest.]