An older woman, usually between 50 and 60, who frequents clubs or venues where blues music is performed. "Bluegars" tend to be highly intoxicated and overly aggressive toward younger men, especially if those younger men are musicians. Unlike "cougars" who are generally attractive older women, "bluegars" are almost never attractive.
Man, did you see that bluegar in the leather jacket? She totally flashed us during the last set and keeps winking at me. She looks like she's been drunk since noon....
A really hot older woman.
Steve's grandma is a real bluegar