Here’s how you can categorize the given words based on the prefixes missing:
Words Missing the Prefix De-
- defounded
- demerit
- decomplete
Words Missing the Prefix In-
- incomplete
- injustice
- inactive
Words Missing the Prefix Over-
- overestimate
- overachieve
- overexpected
Words Missing the Prefix Un-
- unfrost
- unthrone
- unjust
These categorizations are based on the meanings of the respective prefixes you provided. If you need help with anything else, feel free to ask!