Wikipedia
Etymology
The English letters form a backronym of the Japanese phrase 「ヤマなし、オチなし、意味なし」 (yama nashi, ochi nashi, imi nashi), often translated into English as, "no climax, no punch line, no meaning," or as the catchphrase, "No peak, no point, no problem." It has also been humorously interpreted as "Yamete! Oshiri ga itai!" or "Stop! My butt hurts!" in English.
