An assemblage of items that are loosely related. Generally considered to be nearly random in composition. The items grouped together are often odd, uncommon, greatly varied, and/or represent nearly every conceivable combination imaginable.
I ordered a packet of wildflower seeds. It was a "duke's mixture" of flowering plants. There were 45 different kinds of seeds in it, and the only thing they had in common was that they all bloomed.
A foul, disgusting, horrible, drink made of a shot of lime juice and another shot of Bailey's Irish Cream.
You drink the lime juice first and hold it in your mouth. You then shot the Bailey's and swish them together in your mouth as though you were using mouthwash.
Within several seconds your mouth will be full of a rancidly textured ball of goop (the "cement"). As a straight male I can't vouch for it but it must be similar to having a mouthful of cum. Swallowing it is even worse.
They are so gross that the clown who buys you one of these is lucky if you don't gob it back in his face.
Better choices can be found in the tags below.
The cement mixer: even more of a painful experience than Tequila slammers or chartreuse.
The act of spreading a person's ass cheeks, and further, deficating into previously stated open anus. Epoxy is then applied to the cheeks and held closed until dry.
"Oh man, check out my butt! I just got a Canadian Cement Mixer from Marco!"