1 to use

2 to employ

3 to have to

4 to eat or drink

5 expense or outlay

6 usefulness

7 hence

8 therefore

1 surname Na

1 those

1 like that

2 in that way

3 or so

4 so

5 so very much

6 about

7 in that case

1 need not

1 to do two things at once (idiom)

2 to multitask

3 to divide one's attention

1 to have an ulterior motive (idiom)

1 to have no other use or purpose (idiom)

1 obstinate and self-opinionated (idiom)

1 lit. why use a pole-ax to slaughter a chicken? (idiom)

2 fig. to waste effort on a trifling matter

3 also written 殺雞焉用牛刀|杀鸡焉用牛刀[shā jī yān yòng niú dāo]