This is the 397th most frequent Vietnamese word.
lào
The Vietnamese word "lào" can mean "Laos" (a country) or refer to "tuberculosis" (a disease).
Here, 'Lào' is used as a proper noun, referring to the country Laos.
Bạn đã từng đến Lào chưa?
Have you ever been to Laos?
In this sentence, 'lao' is used as a noun, referring to the disease tuberculosis in Vietnamese.
Khi bị bệnh lao, bạn cần được chữa trị kịp thời.
When having tuberculosis, you need timely treatment.
Here, 'láo' derived from 'lào' (in certain contexts) means to emphasize something vigorous or rash.