プログレッシブ和英中辞典(第4版)の解説
ついで【▲序で】
ついでの節はお立ち寄りください
Please call on me if you happen to come this way.
ついでの折にこれを調べてくれ
Please check on this when you have an opportunity.
ジョンの話が出たついでだが，彼のお母さんはどうしておられますか
Speaking of John, I wonder how his mother is doing?
ついでながら彼は今どこにいるのか
By the way, where is he now?
講演のついでに自分の著書についてしゃべった
He 「mentioned his own book in passing [made a passing reference to his own book] during the lecture.
私はあの人が嫌いだが，ついでに言えば皆もそうだ
I dislike him, and, for that matter, so does everyone else.