-(으)ㄹ세라 — For fear that, Lest, Worried that

This expression is used to indicate that the speaker’s anxiety or worry about the occurrence of the content of the preceding clause forms the reason or basis for doing the action stated in the following clause.

Details

This expression can be replaced with -(으)ㄹ까 봐 with no major change in meaning. However, note that -(으)ㄹ세라 has a slightly more literary and old-fashioned nuance.

아내는 아이들이 추울까 봐 장갑에 목도리까지 하게 했다.

세영이는 자신의 하얀색 원피스에 뭐라도 묻을까 봐 무척이나 조심을 했다.

아내는 아이들이 추울세라 장갑에 목도리까지 하게 했다.

Worrying that the children would be cold, my wife made them wear gloves and scarves.

세영이는 자신의 하얀색 원피스에 뭐라도 묻을세라 무척이나 조심을 했다.

Seyoung was extremely careful with her white dress out of fear that she would get a stain on it.

강연자의 이야기를 한마디 라도 놓칠세라 청중들은 부지 런히 메모를 했다.

The members of the audience diligently took notes lest they miss even a word that the speaker was saying.