There are 15 10-letter words that start with 'cong'.
| congealers | congealing | congeneric | 
| congenital | congesting | congestion | 
| congestive | conglobate | conglobing | 
| congregant | congregate | congressed | 
| congresses | congruence | congruency | 
Note: These 15 10-letter words that start with 'cong' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with congr, conge, congl, congo, conga, congi.
5-letter words start with 'cong' (3)