1. the sound a cow makes when it is confused.
2. an expression used to express basic and abstract emotions such as confusion, frustration, depression, joy, boredom, etc.
3. an onomatopoeic expression used when one is beyond all response, either literally or emotionally.
4. a way to describe something that is unfavorable in some way, but not to the extent of being total crap; somewhat bland.
1. farmer: ok, this cow's going to the factory farm.
cow: mur? o__o
2. person 1: so wut did u think of the math test?
person 2: mur...
3. evil physics teacher: ok, so u have to find the wavelength after getting the frequency and speed by finding the spring constant and factoring in the mass of the object in kilograms then converting it so that u get a trajectory and looking for the derivative of time and space.
hapless student: ...mur?
4. man, that movie was so cheesy and... mur.