mutate

This individual has been genetically modified by exposure to a mutagen, by deliberate action via SCIENCE!!, or by who knows what other kind of freak accident.

1. If the individual was in a lab accident and developed superpowers as a result, that's a mutate.
2. If the individual experimented on themself, or volunteered as the subject of someone else's test runs, that's a mutate.
3. If a Gadget went kaplooey! after which the individual could suddenly defy the known laws of physics, that's a mutate.
4. If the villain organization Infinity Inc is anywhere in their background, that individual is most definitely a mutate.
5. If the individual had any kind of precipitating experience before which they were observably a normal human, but now they have super powers: they are probably a mutate.

The term "mutate" is seldom used because it is considered derogatory. Most people instead use the catchall term of "metahuman".
It is possible to be both a mutate and a mutant, just to make things more confusing.