There are 18 words that start with 'rapi'.
| rapid | rapids | rapier |
| rapine | raping | rapini |
| rapist | rapider | rapidly |
| rapiers | rapines | rapists |
| rapidest | rapidity | rapiered |
| rapidness | rapidities | rapidnesses |
Note: These 18 words that start with 'rapi' are found from the USA & Canada version of the tournament Scrabble word list.