adjective
adult, grown-up
B1
Erwachsen: adjective meaning 'adult' or 'grown-up'. It’s non-gradable (not comparative/superlative) and originates from the participle of 'erwachsen'. Used adjectivally to describe people or behavior; antonym 'kindisch'. Note: the noun for an adult is 'der Erwachsene', different inflection. Common collocations: 'erwachsen sein' and 'erwachsene Person'.
Examples
Als erwachsene Person musst du Verantwortung übernehmen.
As a grown-up, you have to take responsibility.
Die Tochter war bereits erwachsen, obwohl die Eltern weiterhin Regeln aufstellten.
The daughter was already an adult, although the parents continued to set rules.
Er ist jetzt 18 und offiziell erwachsen.
He's now 18 and officially an adult.
Details
Mnemonics
Picture a small child turning into a taller person standing confidently
Sounds a bit like 'air-wax-en' — picture someone growing up taller
Notes
Erwachsen is often used as an adjective meaning adult; it can also be used as a noun (der/die Erwachsene). It is a participial adjective and is typically not graded.