This is the 2022nd most frequent Korean word.
비
"비" means "rain" in English.
In this sentence, '비' refers to rain, and it is used as a noun to describe the weather condition.
어제 밤에 많은 비가 내렸어요.
It rained a lot last night.
Here, '비' is part of the compound word '비행기' (airplane), where it contributes the meaning of 'fly'.
비행기를 타고 제주도에 갔어요.
I went to Jeju Island by airplane.
In this case, '비' is part of the word '비싸다', which means 'expensive,' and it indicates high cost.