Height is 'a function of' age in children. [=the height of children increases as their age increases]
His bad health has prevented him from being able to 'function' effectively in recent weeks.
Her chief/main/primary/principal 'function' is to provide expert legal advice.
(..) I had this whole... da-da-da-da-da-da. No sitting. Can't you see I'm reading a very important chart here? A british tabloid? This functions as my shield to protect me from those who would annoy me. Hey, Dr. C. Shield on. (..)2010 TvShow: Scrubs Title: Our Thanks Season: 9 Episode 13