Top definition
A type of poster on Reddit, usually in the Ask Reddit sub. Starts off post with, "Not a -------, but". Severely annoying and disrespectful, since they are blatantly ignoring OP's question.
OP="Train conductors of Reddit, what is the weirdest story you have?"
Not-a-but= Not a train conductor, but my (aunt, brother, grandpa, great uncle,) saw a headless body being drug down the track by a mutant coyote.
by chadww August 04, 2016
Get the mug
Get a Not-a-but mug for your father Bob.