There are 11 13-letter words that start with 'del'.
| delaminations | delectability | 
| deleteriously | deliberations | 
| delicatessens | deliciousness | 
| delightedness | delimitations | 
| delinquencies | deliquescence | 
| deliriousness | |
Note: These 11 13-letter words that start with 'del' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with deli, dele, delu, dela, delo, delt, delf, delv, delp, dell, dels.
4-letter words start with 'del' (6)