The Vietnamese word "nguội tanh" typically refers to something that is cold and unappetizing, especially food that has lost its freshness and taste. It can be used to describe food that has been left out for too long, becoming unappealing and not suitable for consumption.
In a broader sense, "nguội tanh" can also describe situations, feelings, or relationships that have become dull, stale, or lacking in enthusiasm. For example, you might say a conversation feels "nguội tanh" if it is boring and lacks energy.
While "nguội tanh" primarily relates to food, it can also metaphorically apply to things that have lost their appeal or freshness, such as "nguội tanh" relationships or discussions.