There are 15 12-letter words that start with 'ser'.
| seraphically | serenenesses | sericultural |
| sericultures | serigraphers | serigraphies |
| seronegative | seropositive | seropurulent |
| serotonergic | serpentinely | servanthoods |
| serviceberry | servicewoman | servicewomen |
Note: These 15 12-letter words that start with 'ser' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with seri, serv, sero, sere, serr, sera, serg, serm, serp, serf, serj, seru, serd, sers.
4-letter words start with 'ser' (4)