The Vietnamese word "ngáo" is primarily used as an adjective and can mean "dull" or "stupid." It's often used in informal contexts to describe someone who is not thinking clearly or who lacks common sense.
In more advanced contexts, "ngáo" can also refer to someone who is out of touch with reality or who has difficulty understanding things, particularly in social situations. It can sometimes carry a playful or teasing tone among friends.
While "ngáo" mainly conveys the idea of being dull or stupid, it can also be used affectionately among friends to tease each other about being silly or goofy.
When using the word "ngáo," it's important to consider the context and the relationship you have with the person you are describing. It can be light-hearted among friends, but it can also be offensive if used in a more serious context.