An unexpected occurrence or a turn of events that is unfavorable.

अनपेक्षित घटना या दुर्भाग्यपूर्ण स्थिति

English Usage: His career took a dusfall when he lost his job unexpectedly.

Hindi Usage: जब वह अचानक अपनी नौकरी खो गया तो उसकी करियर में एक dusfall आया।