質問: The word 大忙{おおいそが}し is classified as a noun or a na-adjective. If I analyze it correctly, the word 大忙し consists of the prefix (接頭語) "大" and the i-adjective stem of "忙しい." In addition, there is no such i-adjective as "大忙しい." Out of curiosity, I'd like to ask if anyone knows other compound words that end with an i-adjective stem and are only used as a noun or a na-adjective (its i-adjective form doesn't exist).
回答: Many adjective stems work like a standalone noun or an element of a compound, for example: * 丸い - 丸太 - 赤丸 - 丸 * 悪い - 悪者 - 性悪 - ワル * 黒い - 黒子 - 中黒 - 黒 * 長い - 長靴 - 気長 * 軽い - 軽業 - 手軽 * 辛い - 辛口 - 激辛 * 厚い - 厚着 - 肉厚 * 安い - 安物 - 株安 * 生臭い - 生臭坊主; 有難い - 有難迷惑; 面白い - 面白サイト * 短い - 手短; ヤバい - 激ヤバ * 古い - お古; めでたい - おめでた If you are looking for words like these, the list would be very long. However, 大忙し is different from these in that 忙し seems to be working like a noun *along with okurigana*. And I think such words are rare. * 柔らかい - 柔らか頭 - お手柔らか (But 柔らか may be a distinct na-adjective) * 嬉しい - 嬉し泣き; 苦しい - 苦し紛れ (But the stems do not come at the end of a compound) * 愛しい - 愛し(の); 懐かしい - 懐かし(の); 麗しい - 麗し(の) (But these are not compounds) I could think of no word that is perfectly like 大忙し...