プログレッシブ和英中辞典(第4版)の解説
－だの
彼女はピアノだのフルートだのを稽古(けいこ)している
She takes lessons in piano, flute, and so forth.
忙しいだの病気だのと言ってちっとも約束を守らない
He never keeps his promises, saying he is too busy, or he is not well, or something.／He keeps breaking his promises on the pretext of pressure of business, ill health or whatnot.
彼はなんだのかんだのと文句ばかりを言っている
He is always complaining about 「this and that [one thing or another].