The Vietnamese word "nghẹn lời" means "to be struck dumb" or "to be unable to speak" due to strong emotions, often feelings of sadness, joy, or surprise. When someone experiences an overwhelming emotion, they may find it hard to express themselves verbally, and that is when we use "nghẹn lời."
While "nghẹn lời" primarily refers to being silent due to emotions, it can also imply a feeling of being overwhelmed in other contexts, such as being speechless due to shock or disbelief.