This is the 4655th most frequent German word.
untersagt
"Untersagt" means "prohibited."
In this sentence, 'untersagt' is used as an adjective to inform that smoking is formally forbidden.
Das Rauchen ist hier strengstens untersagt.
Smoking is strictly prohibited here.
Here, 'untersagt' again functions as an adjective indicating that entry is officially not allowed during specific hours.
Der Zutritt zum Gebäude ist nach 18 Uhr untersagt.
Entry to the building is prohibited after 6 PM.
In this example, 'untersagt' describes a formal prohibition regarding acts of photography.