" low-grade "

 [ "low grade" ]

1: A derogatory term used by mentally challenged or very low IQ institutionalized males or females used to put down another mentally challenged person. Sometimes used against their careworkers. Normally used in a retallitory manner and refering to the others IQ. I personally never experienced this term outside of an institutioanlized situation. And found this was this worst verbal insult said person could use. If you are called a low grade you have not been complimented. I like to used the term in the car to prevent road rage as it is safe around children and it really helps as only I (until now) know how bad I've insulted the driver of the other vehicle.

  * e.g.,  ... Oh you think I'm a dummy. Well you're a low grade. Low grade, low grade, low grade! 

 [ "Low Grade Blues" ]

1: The phenomenon of posting online about a graded collectible whereby the original poster will always apologize for the low quality of said collectible.

  * e.g.,  ... "Just bought a new-to-me copy of Avengers #1, sorry for the low grade." Got them Low Grade Blues