There are 12 words that start with 'cogi'.
| cogito | cogitos | cogitate | 
| cogitable | cogitated | cogitates | 
| cogitator | cogitating | cogitation | 
| cogitative | cogitators | cogitations | 
Note: These 12 words that start with 'cogi' are found from the USA & Canada version of the tournament Scrabble word list.