I had this argument with a few physicians my wife works with that we had at a party a couple of years ago. I've always refused to call a physician "doctor" and was arguing with the MDs that they were clinicians, not doctors; for, doctors wrote and defended dissertations and mds did not. After quite a few beers and a visit to m-w.com, they all agreed that "clinician" fit them better than "doctor". So, when I say "clinician" I mean "physician". One of them even introduces himself as "Clinician X" to patients in the ER now. ;0)