There are 12 words that start with 'declin'.
| decline | declined | 
| decliner | declines | 
| decliners | declining | 
| declinist | declinable | 
| declinists | declination | 
| declinations | declinational | 
Note: These 12 words that start with 'declin' are found from the USA & Canada version of the tournament Scrabble word list.