He died of 'natural causes'. [=he died because he was ill or old and not by being killed in an accident, battle, etc.]
She was adopted immediately after she was born and never knew her 'natural' [=(more commonly) 'birth'] parents.
a country rich in 'natural resources' [=a country that has many valuable plants, animals, minerals, etc.]
(..) So, I've been analyzing the gem... ...inside...you may recognize... - Jarvis. - Doctor. Started out, Jarvis was just a natural language UI. Now he runs the Iron Legion. He runs more of the business than anyone besides Pepper. - Oh. - Top of the line. - Yes. I suspect not for long. (..)2015 Avengers: Age of Ultron