der Profi
Translation
pro, professional
Examples
Er ist ein echter Profi in seinem Job.
He is a real pro at his job.
Das wurde von Profis gemacht.
That was done by professionals.
Grammar Patterns
to be a pro ((in/at sth.)) Er ist ein Profi in seinem Fach.
Similar Words
Synonyms: Experte (expert), Fachmann (specialist); Antonym: Amateur
Etymology
A clipping of 'Professional', which comes from the Latin 'profiteri', meaning 'to declare publicly'.
Memory Tips
It's the same as the English slang 'pro'. Very easy to remember. Note the masculine article: 'der Profi'.