◆on the side
(in addition to usual)顺便；附带；另外
I'm trying to find a way of earning extra money on the side.我正试着找法子赚点儿外快。
(secretly)秘密地；背地里
He has a girlfriend on the side.他背地里有个女朋友。
(with main dish)作为配菜
Serve a bowl of warm tomato sauce on the side.上一碗热番茄酱做配菜。