Noun

(en noun)

A person who practices a profession or art, especially law or medicine.

*{{quote-magazine, date=2014-06-21, volume=411, issue=8892, magazine=(The Economist)

, title= Magician’s brain , passage=The [Isaac] Newton that emerges from the [unpublished] manuscripts is far from the popular image of a rational practitioner of cold and pure reason. The architect of modern science was himself not very modern. He was obsessed with alchemy.}}

One who does anything customarily or habitually.

(label) A sly or artful person.

* John Whitgift

the men of St. John's were cunning practitioners , in shaking off their Masters and Heads.

Noun

(wikipedia executor) (en noun)

A person who carries out some task.

(label) Someone appointed by a testator to administer a will; an administrator.

(obsolete) An executioner.

* 1599 , , I. ii. 203:

The sad-eyed justice, with his surly hum, / Delivering o'er to executors pale / The lazy yawning drone.