The term 'PREFIX FOR PHONE' can be solved by two crossword solutions: TELE and MEGA. TELE is derived from the Greek word for 'far off' and is used to refer to communication over a distance. MEGA is derived from the Greek word for 'GREAT' and is used to refer to something that is very large or powerful. Both terms are commonly used as prefixes for phone numbers, indicating the type of service being provided.