This is the 456th most frequent Finnish word.
entinen
Former; previous.
In this sentence, 'entinen' is used to mean 'former', indicating a previous state or role of someone.
Hän on minun entinen opettajani.
He/She is my former teacher.
Here, 'entinen' is used to denote a previous usage or designation of a building.
Vanhan kaupungin entinen kirkko on nykyään museo.
The old town's former church is now a museum.
In this context, 'entinen' refers to a prior or former time period of a person's life.