There are 11 words that start with 'collag'.
| collage | collaged | collagen | 
| collages | collagens | collaging | 
| collagist | collagists | collagenase | 
| collagenous | collagenases | |
Note: These 11 words that start with 'collag' are found from the USA & Canada version of the tournament Scrabble word list.