noun

• (usually in the plural, informal) A feeling of sadness or depression.
• (singular or plural, informal) One's particular life experience, particularly including the hardships one has faced.
• (singular or plural, informal) The negative emotional state produced by a particular action, occupation, experience or idea.
• (music) A musical form, African-American in origin, generally featuring an eight-bar or twelve-bar blues structure and using the blues scale.
• (music, always singular) A musical composition following blues forms.
• A uniform made principally of a blue fabric, and especially a full dress uniform thus colored.
• (drug slang) Any of various blue pills sold on the street, mimicking the appearance of prescription pain killer tablets but often laced with fentanyl that leads to overdose deaths (see opioid epidemic).
• (informal) any of several sports teams whose uniform is predominantly blue, such as:
• (Australian rules football) Carlton Football Club.
• (rugby league) New South Wales.
• (soccer) Birmingham City FC.
• (soccer) Everton FC.
• (soccer) Chelsea FC.
• (soccer) Manchester City FC.