A Locum (Loci?)
The various medical facilities seem to have a fair number of these, nowadays.
I'm told that it's a "Good Little Earner" as the Locum can negotiate his/her terms & conditions with whatever facility/practice has a slot.
It is said that a Locum can pick & chose what days, weeks times he will work, and where.
It's a self employment operation, sorting your own tax, etc.
It's said that we can pay double, or more, for a locum, especially when times are tough.
I'm not suggesting that they are bad, The last one I went to was the best in the practice (in my opinion) for the time he was there.
He put the customer first, paid attention to what was said, and worked to get a result. That is not always the experience.
Thing is, it's costing the NHS dearly.
We need more Doctors & payment for quality.