1 old variant of 深[shēn]

1 Shenzhen subprovincial city in Guangdong, special economic zone close to Hong Kong

1 plowing and weeding

2 farm work

3 fig. to work or study diligently

1 to deepen

1 to penetrate deeply

2 thorough

1 to talk intimately while being comparative strangers (idiom)

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

1 in the dead of night (idiom)

1 the implied message is deep (idiom); having deep implications