There are 21 words that start with 'expi'.
| expire | expiry | expiate | 
| expired | expirer | expires | 
| expiable | expiated | expiates | 
| expiator | expirers | expiries | 
| expiring | expiating | expiation | 
| expiators | expiatory | expiations | 
| expiration | expiratory | expirations | 
Note: These 21 words that start with 'expi' are found from the USA & Canada version of the tournament Scrabble word list.