Ejercer una Profesión.

To practice (AmE), to practise (BrE)

My aunt is a lawyer, but she doesn't practice.

In News:

"Given that Murray is now a convicted felon who has been found guilty of homicide in California, Cooley said the doctor will lose his license to practice medicine in the state. He added that he hoped other states would follow suit and revoke Murray's right to practice medicine as well. "

MTV Online.

"Dr. Conrad Murray, 58, sat stone-faced, his chin held high, as he heard the verdict that could send him to prison for up to four years and cost him his license to practice medicine. He was handcuffed and immediately led off to jail without bail to await sentencing Nov. 29."

CBS News.

In Dictionaries:

"How long have you been practising as a dentist?"
Cambridge Dictionary Online.

"She practised medicine for twenty years."
Cambridge Dictionary Online.