The Vietnamese word "đông đúc" is an adjective that translates to "crowded" or "dense" in English. It is used to describe places or situations where there are a lot of people or things packed closely together.
Người dân ở thành phố vào giờ cao điểm thường thấy rất đông đúc.
(People in the city during rush hour often see it very crowded.)
Chợ Tết năm nay đông đúc hơn mọi năm.
(The Tet market this year is more crowded than in previous years.)
While "đông đúc" primarily means "crowded," in some contexts, it can imply a lively atmosphere due to the presence of many people.