is a Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

ese pop culture word originated by comedian Ken Shimura

Ken Shimura

, is a Japanese comedian and actor. He co-starred with Masashi Tashiro, Nobuyoshi Kuwano in the Japanese variety show "Ken Shimura no Bakatono-sama"....

 for his Bakatono character (a fool/clown in white makeup and Japanese garb). Usually, it's said while making a slicing motion under the chin and grimacing. The word was further popularized by the popular all-girl quartet Minimoni (ミニモニ。), who features the character in two of their promotional videos ("Aiin! Dance no Uta" and "Aiin Taisō").

What the word means has been a matter of debate. One source suggests it means, "Enough!", and the slicing gesture makes this a reasonable if not completely credible definition. Most seem to feel that Aīn is a nonsense word

Nonsense word

A nonsense word, unlike a sememe, may have no definition. If it can be pronounced according to a language's phonotactics, it is a logatome. Nonsense words are used in literature for poetic or humorous effect. Proper names of real or fictional entities are sometimes nonsense words.-See...

, used primarily for comic effect.