Feature phone is a euphemism for dumb phone.
Waterproof, 8M camera, snapdragon chipset, full email, GPS and BREW apps, NFC, running 240 hours.
There's quite a gap with a "dumb" phone.
Or the other way around? I prefer the phrase "feature phone". "Dumb phone" sounds unneccesarily derogotary and condescending. Most of the world's population has a "dumb phone".