There are 12 13-letter words that start with 'sec'.
| secessionisms | secessionists |
| seclusiveness | secobarbitals |
| secondariness | secretagogues |
| secretaryship | secretiveness |
| sectarianisms | sectarianized |
| sectarianizes | sectionalisms |
Note: These 12 13-letter words that start with 'sec' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with secu, secr, sect, seco, sece, secl, seca, secc, secp, secs.
4-letter words start with 'sec' (2)