yǐ​fáng

prevent

以防 yǐ​fáng
prevent conjunction
used as a conjunction meaning so as to avoid or prevent a negative outcome

He installed iron bars on the windows to prevent thieves from entering.

in case verb
as a precaution against a possibility; just in case

You'd better bring a jacket in case the weather gets cold.

Frequency

Movie subtitles
2.03 per million appears in 1% of films
Written text
6.28 per million

Sources

Definitions
CC-CEDICT