This is the 4242nd most frequent Polish word.
dorosłej
"Dorosłej" means "adult" or "mature" (feminine singular form) in English.
Here, 'dorosłej' functions as an adjective in the genitive singular form, modifying 'osoby' (person), describing someone of adult age.
Nie zapomnij zabrać dorosłej osoby na wycieczkę.
Don't forget to bring an adult person on the trip.
In this case, 'dorosłej' acts as an adjective in the dative singular form, agreeing with 'publiczności' (audience), indicating that the audience is mature.
Ta książka jest napisana z myślą o dorosłej publiczności.
This book is written with the adult audience in mind.
Here, 'dorosłej' is an adjective in the genitive singular form, describing 'obecności' (presence), implying the need for attendance of adults.