ダメダメ Also written だめだめ, 駄目駄目 Meanings な-adjective entirely useless; completely worthless See also: 駄目 (だめ). Interjection no no; don't! See also: 駄目 (だめ). Example sentences 私の文法はダメダメです。My grammar is poor. この検索エンジン、ダメダメね。This search engine is terrible. Jinuma: Japanese Dictionary · Word lists