practicing (adj.)

late 14c., practisen, "to follow or employ" a course of action; c. 1400, "to do, put into action or practice;" from Old French pratiser, practiser "to practice," alteration of practiquer, from Medieval Latin practicare "to do, perform, practice," from Late Latin practicus "practical," from Greek praktikos "practical" (see practical).

From early 15c. as "to carry on a profession," especially medicine; also "to do or perform repeatedly or habitually with the object of acquiring skill, to learn by repeated performance;" from mid-15c. as "to perform, work at, exercise." Intransitive sense of "perform certain acts repeatedly, train one's self" is by 1590s. Sense of "to cause to practice, teach by exercise, train, drill" is from 1590s. Related: Practiced; practicing.