I had lunch at Carmelo's with friends yesterday and the conversation turned to hospitals and doctors and such.
"We were at the hospital," said Robin, "And the...he...the doctor...."
Robin paused and looked confused. We all looked at her.
"What do you call those doctors who know their shit?" she asked.
"Specialists?" I offered.
"Yeah! That's it," she said. "We were at the hospital and the specialist came in...."
Personally, I prefer to think of them as guys who know their shit.