Practiced as one's main profession or primary activity, which one mainly lives from. It stands in contrast to nebenberuflich (as a side job) or ehrenamtlich (voluntary/unpaid).
example
Sie arbeitet hauptberuflich als Ärztin und engagiert sich ehrenamtlich im Tierschutz.
She works full-time as a doctor and volunteers in animal welfare.
Usage tips
Word composition
The word is made up of 'Haupt-' and 'beruflich'. Here, 'Haupt-' means 'most important' or 'primary', so it describes the activity that makes up the most important part of one's professional life.
EXAMPLE
Sein Hauptberuf ist Ingenieur.
His main profession is engineer.
Adverb or adjective
'Hauptberuflich' can be used as an adverb to describe a verb, or as an adjective before a noun. As an adverb, it answers the question 'How?'.
EXAMPLE
Er ist hauptberuflich Musiker.
He is a full-time musician.
Typical context
The word is often used to distinguish one activity from others. Common opposites are 'nebenberuflich' (as a side job) or 'ehrenamtlich' (voluntary/unpaid).
EXAMPLE
Sie ist hauptberuflich Übersetzerin, aber nebenberuflich gibt sie Yogakurse.
She is a full-time translator, but she also teaches yoga classes as a side job.
Compare with
antonym
hauptberuflich vs nebenbei
on the side / incidentally
'nebenbei' and 'hauptberuflich' are opposites in a work context. 'nebenbei' means that someone does an activity in addition to something else, so not as their most important work. 'hauptberuflich' means that this activity is their main profession and what they mainly live from. So the difference is the role of the activity: additional or central. 'nebenbei' fits for hobbies, small jobs, or extra tasks. 'hauptberuflich' fits for the most important professional activity.
hauptberuflich
Die Chefin ist hauptberuflich Ärztin, obwohl sie auch Kurse gibt.
The boss works full-time as a doctor, although she also teaches courses.
nebenbei
Paul arbeitet im Büro und verkauft nebenbei selbst gemachten Schmuck.
Paul works in an office and sells handmade jewelry on the side.