Ruin
Part of speech: noun
Definition: construction withered by time. The state of being a ruin, destroyed or decayed. Something which leads to serious troubles.
Part of speech: verb
Definition: to cause the ruin of.
Example sentence: You have been trapped in the inescapable net of ruin by your own want of sense.
Downfall
Part of speech: noun
Definition: A precipitous decline in fortune; a rapid deterioration, as in status or wealth.The cause of such a fall; a critical blow or error.
Example sentence: Women are what completely inspire me, and they have also been my downfall.