This is the 3437th most frequent Polish word.
zamknięty
"Zamknięty" means "closed" in English.
Here, 'zamknięty' is used as a past participle adjective meaning 'closed', in the context of indicating the state of the store being closed on the specific day.
Sklep jest zamknięty w niedziele.
The store is closed on Sundays.
In this sentence, 'zamknięty' describes a personality trait, metaphorically indicating someone who is reserved or introverted.
On jest osobą zamkniętą w sobie.
He is a withdrawn person.
'Zamknięty' as a past participle is used in the passive voice to indicate that the action of locking has been completed on the door.