There are 18 words that start with 'leuc'.
| leucin | leucine | leucins | 
| leucite | leucoma | leucemia | 
| leucemic | leucines | leucites | 
| leucitic | leucomas | leucemias | 
| leucocyte | leucocidin | leucocytes | 
| leucoplast | leucocidins | leucoplasts | 
Note: These 18 words that start with 'leuc' are found from the USA & Canada version of the tournament Scrabble word list.