Noun

2. A feeling of sadness or depression.
   • 1883: Robert Louis Stevenson, Treasure Island

     If we had been allowed to sit idle we should all have fallen into the blues...

3. (singular or plural) One's particular life experience, particularly including the hardships one has faced.

   Your blues is just like mine.

   Your blues are just like mine.

4. A musical form, African-American in origin, generally featuring an eight-bar or twelve-bar structure and using the blues scale.

   Many great blues musicians came from the Mississippi Delta region.

   A large portion of modern popular music is influenced by the blues.

5. A musical composition following blues forms.

   My next number is a blues in G.

6. A uniform made principally of a blue fabric.

   The marched in their dress blues.