unseriös
Translation
disreputable, dubious, unprofessional, shady
Examples
Das ist ein unseriöses Angebot.
That is a dubious offer.
Sein Verhalten wirkt sehr unseriös.
His behaviour seems very unprofessional.
Grammar Patterns
sth. is unseriös sth. is disreputable The offer is unseriös.
an unseriös [noun] a dubious... an unseriös business
Similar Words
Synonyms: zweifelhaft (doubtful), fragwürdig (questionable); Antonyms: seriös (reputable), vertrauenswürdig (trustworthy)
Etymology
From un- (not) + seriös (serious, reputable). Literally 'not serious/reputable'.
Memory Tips
It looks like 'un-serious', but the meaning is stronger, implying something is untrustworthy or shady, not just not funny.