There are 12 words that start with 'readd'.
| readd | readds | readded | 
| readdict | readding | readdicts | 
| readdress | readdicted | readdicting | 
| readdressed | readdresses | readdressing | 
Note: These 12 words that start with 'readd' are found from the USA & Canada version of the tournament Scrabble word list.