The fourth character is the idiom of "Shen", the last character of the four-character idiom ending with "Shen" and its explanation:
Shenzhou Lu Shen - Shenzhou: refers to China; Lu Shen : Land sinks without water. Mainland China is sinking. It is a metaphor for territory being invaded by the enemy.
Lifeless - describes an atmosphere that is not lively. It also describes a person who is depressed and unable to cheer up.
Follow the trend - you don't have any specific ideas, just follow the trend.
The wild goose disappears and the fish sinks - a metaphor for the loss of news.
The jade is broken and the beads sink - a metaphor for the death of a beautiful woman.
The moon sets and the stars sink - the moon sets and the stars dim. It means when the sky is about to break.
Gloomy and depressed - refers to annihilation and disappearance.
Float or sink according to the world - either float or sink according to the world. Refers to the ability to change with changes in the world or the current situation.
There is no trace of letters and no news at all.
The ups and downs of officialdom - refers to the twists and turns of official career, which are unpredictable.
Drowsy - describes a person's state of confusion.
Muddy and heavy - a vast look.
Dusk is heavy - Muqi: the mist at dusk; Shen Shen: low. Describes a lack of energy and lack of vitality.
The rabbit rises and the black sinks - refers to the moonrise and sunset.
The rabbit is missing and the black bird is sinking - the rabbit is missing and the black bird is flying. Describes the rapid passage of time.
The geese are cut off and the fish sinks - a metaphor for cutting off information from each other. Same as "the geese pass away and the fish sink".
The geese pass away and the fish sink - a metaphor for cutting off communication with each other. Also known as "the wild goose breaks and the fish sinks".
Follow the world - go with the flow and conform to the world.
The words are serious and the heart is heavy - the words are sincere and the heart is heavy.
Jade and stone sink together - a metaphor for good and evil suffering together.