ruin
The French word 'ruine' is used in a similar way to its English counterpart 'ruin'. It can refer to the state of a structure or a place that has been destroyed or is in a state of severe disrepair. It can also be used metaphorically to describe the complete destruction of someone's plans, hopes, or finances. For example, 'La guerre a laissé le pays en ruine' means 'The war left the country in ruins'.
The war left the country in ruins.
This sentence uses 'ruine' in the phrase 'en ruine', which refers to something being destroyed or in a state of disrepair, typically after a disaster or war.
He lost all his money and now he is in ruin.
In this sentence, 'ruine' conveys a metaphorical ruin than a physical one, referring to financial ruin.
The castle is a ruin after the fire.
In this context, 'ruine' is used in a literal sense to describe a building (in this case, a castle) that has been severely damaged or destroyed, in this situation, by a fire.