1 old variant of 深[shēn]

1 variant: 夜 yè

1 midnight

2 in the middle of the night

1 nightclub

1 nighttime

2 evening or night (e.g. classes)

1 to talk intimately while being comparative strangers (idiom)

1 lit. to make night as day (idiom); fig. to burn the midnight oil

2 work especially hard

1 to make day as night (idiom, from Book of Songs); fig. to prolong one's pleasure regardless of the hour

1 untold pain and suffering (idiom); deeply scarred for life

1 If you work at it hard enough, you can grind an iron bar into a needle.

2 cf idiom 磨杵成針|磨杵成针, to grind an iron bar down to a fine needle (idiom); fig. to persevere in a difficult task

3 to study diligently