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.
(..) But thanks to recent advances in stem cell research... and the fine work of Doctors Krinski and Altschuler... Clevon should regain full reproductive function. Get your hands off my junk! Unfortunately, Trevor passed away from a heart attack... while masturbating... (..)2006 Idiocracy