There are 12 11-letter words that start with 'lam'.
| lambrequins | lamebrained | lamellately | 
| lamellicorn | lamelliform | lamentation | 
| laminarians | laminations | laminitises | 
| lammergeier | lammergeyer | lamplighter | 
Note: These 12 11-letter words that start with 'lam' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with lamb, lame, lamp, lami, lamm, lama, lams.
4-letter words start with 'lam' (5)