What are the meanings of the word 'blues'?

Meaning of 'blues':

• Musicians usually say: 'Blues is when a good man feels sad and lonely.'
• Dictionaries define it as a feeling of deep unhappiness.
• It was an emotion long before it became a kind of music.

Answer: The word 'blues' can refer to a musician's saying about sadness and loneliness, or a dictionary definition of deep unhappiness, and it originated as an emotion before becoming music.