'Worsening' is the -ing form of the verb 'worsen', which means to become worse, or to make something worse. It works both ways: a situation can worsen by itself ("His health worsened over the winter"), or something can worsen it ("The rain worsened the traffic"). As 'worsening' it does two jobs. It is the ordinary continuous form of the verb — "Her eyesight is worsening" — and it also sits in front of a noun to describe a thing that is getting worse right now: "worsening weather", "a worsening economy", "worsening relations between the two countries". Used that way it feels like an adjective, and this is probably where you will meet it most, because it is a favourite of news writers. There is also a noun use, less common: "a worsening of the situation". Notice what 'worsen' does NOT cover: it is almost never used about people's behaviour or about small everyday annoyances. We do not say "my mood worsened" or "the food worsened" — we say "got worse". 'Worsen' and 'worsening' belong to serious, often written or formal contexts: illness, weather, economies, wars, pollution, shortages, conflicts, conditions. So a doctor writes "the patient's condition is worsening" but tells the family "he's getting worse". Both mean the same; one is a report, one is a conversation. If you are ever unsure whether 'worsen' fits, ask yourself whether the thing is big and serious enough to be in the news. If not, 'get worse' is the safe and natural choice — and 'get worse' is never wrong, even in the serious cases.