be (not) (one's) department

To be one's area of expertise or responsibility. I can't approve expense reports—that's not my department. Car repair is my dad's department, so he should be able to help you out.

Common Names:

Name	Pronounced	Usage
Marcas	-	Irish, Scottish
Kyrsten	-	English (Rare)
Alojzy	ah-LOI-zi	Polish
Lucine	-	Armenian
Kuno	KOO-no (German)	German, Ancient Germanic
Isabelle	ee-za-BEL (French), IZ-ə-bel (English), ee-sah-BEL-lə (Dutch)	French, English, German, Dutch