The Vietnamese word "hoàng thái tử" translates to "crown prince" in English. A crown prince is the son of a king or queen who is first in line to inherit the throne. This title indicates that the person is expected to become the next ruler of the kingdom.
In historical contexts, "hoàng thái tử" can refer to specific individuals in Vietnamese history, such as the crown princes of different dynasties. You might see it in discussions about Vietnamese history or royal lineage.
While "hoàng thái tử" specifically refers to a crown prince, the term could also be used metaphorically in literature or speech to describe someone who is seen as the future leader or successor in a non-royal context.