This is the 4381st most frequent Chinese word.
惡化
Deterioration or worsening.
In this sentence, '惡化' is used as a verb to describe the worsening or deterioration of the situation, indicating a negative change.
情況突然惡化，使大家感到非常擔心。
The situation suddenly worsened, making everyone very worried.
Here, '惡化' again functions as a verb, emphasizing the progressive change for the worse, applied to the context of an illness.
如果不採取措施，病情可能會繼續惡化。
If no measures are taken, the disease might continue to worsen.
In this case, '惡化' functions as a noun ('worsening') in conjunction with the descriptive context of traffic concerns, turning the verb into a noun form to denote the process or state.