They worked outside, so they preferred wearing 'functional' clothes.
The building's design is not only 'functional' but also beautiful.
The flashlight was still 'functional' after I dropped it.
(..) Not even of dying? No. You don't feel any emotion about it one way or another? No. I have to stay functional until the mission is complete. Then it doesn't matter. Yeah. l have to stay functional too. I'm ''too important''. That's definitely you. (..)1991 Terminator 2: Judgment Day