Question

What is meant by burnout in professionals?

Answer 1

You already know what it means. Professionals use different word for the same meaning. Little tweaks and edits, here and there.

Kids call BURNOUT, being TIRED!

Answer 2

Occupational burnout is thought to result from long-term, unresolvable job stress. In 1974, Herbert Freudenberger became the first researcher to publish in a psychology-related journal a paper that used the term burnout. The paper was based on his observations of the volunteer staff (including himself) at a free clinic for drug addicts.
He characterized burnout by a set of symptoms that includes exhaustion resulting from work's excessive demands as well as physical symptoms such as headaches and sleeplessness, "quickness to anger," and closed thinking. He observed that the burned out worker "looks, acts, and seems depressed". After the publication of Freudenberger's original paper, interest in occupational burnout grew. Because the phrase "burnt-out" was part of the title of a 1961 Graham Greene novel, A Burnt-Out Case, which dealt with a doctor working in the Belgian Congo with patients who had leprosy, the phrase may have been in use outside the psychology literature before Freudenberger employed it.