radio-radio- /reɪdiəʊ $ -dioʊ/ prefix 
technical using radio waves: 
radiopaging (=calling people by radio)
technical using radio waves: radiopaging (=calling people by radio)- investigator
- investigatory
- investiture
- investment
- investment bank
- investment banker
- investment banking
- investment club
- investor
- inveterate
- invidious
- invigilate
- invigilator
- invigorate
- invigorating
- invincibility
- invincible
- inviolability
- inviolable
- inviolate
- invisibility
- invisible
- invisible ink
- Invisible Man
- invisibly