I think Butch has it right. The 2 is the 9, so Am9+ ("Augmented A minor nine") seems to be the best way.
So, for those scoring at home.
A minor is A C and E
An augmented chord is one where the V is raised a half step. In this case, in the key of A minor that would be the F, because a half step above E is F. This is actually one of those cases where it might be OK to call it "E#," even though it "technically" doesn't exist.
So now we have A C F
The B is the II (and the IX) in an A minor scale (A B C D E F G A B). Hence, by adding the B, we are playing the 9 as well. So we end up with an "augmented A minor 9."
A C F B
Notationally, a + is an augmented chord. Am9+
Does it make me weird that I love figuring this stuff out?
Someday we'll win this thing...www.aclosesecond.com