incumbent
noun
1 The holder of an office or post:
the present incumbent will soon be retiring
[EDIT]
Usage [emphasis added]:
Aron & Nightgale, Incumbent Workers' Views about Lifelong Learning, 1995, p.7
… (2) evaluate the individual labor market impacts of increased education and training among incumbent workers.
Sims, Reforming (transforming?) a Public Human Resource Management Agency, 2010, p.234
a. If an active eligibility list for the new classification exists, the incumbent employee was on the eligibility list, and the incumbent employee met all other eligibility requirements, he or she might be appointed from the eligibility list to the reclassified position.
Smyth, Employed but not Engaged, 2010, p.90
If the old role becomes redundant, and a new role created, then there is no absolute obligation to move the incumbent employee over to the new role. That said, you do have an obligation in any redundancy to consider redeployment opportunities for redundant employees, and in this case that would involve offering the new role to the incumbent employee.
Best Answer
apothecary
From a historical stand point,
If you've ever read Romeo and Juliet, you may recall that Romeo purchased his vial of poison from an apothecary illegally.
If you are looking for the modern definition:
Source: Dictionary.com