This is the 1023rd most frequent Russian word.
заболевание
Illness; disease.
In this sentence, the word 'заболевание' is used to mean 'illness,' referring to a general health condition requiring treatment.
Срочное лечение помогло победить заболевание.
Timely treatment helped overcome the illness.
Here, 'заболевание' emphasizes the spread of a specific health condition within a group.
Новое заболевание распространилось среди населения.
A new illness has spread among the population.
In this example, 'заболевание' is used in a medical or scientific context, referring to a specific disease that can be researched and addressed.