This is the 13738th most frequent German word.
engerer
"Engerer" means "closer" or "narrower" in English.
Here, 'engerer' is used to mean 'more restricted' when specifying a more limited context or meaning.
Im engeren Sinne bezieht sich der Begriff nur auf die Hauptbedeutung.
In a narrower sense, the term refers only to the main meaning.
In this sentence, 'engerer' refers to a subgroup of friends who share a closer or more intimate relationship.
Der Kreis der engeren Freunde ist klein und vertraut.
The circle of closer friends is small and familiar.
'Engerer' here describes the action of narrowing or focusing the scope onto a more specific or limited academic discipline.