There are 11 14-letter words that start with 'semi'.
| semiautomatics | semiautonomous |
| semicentennial | semicommercial |
| semiconducting | semiconductors |
| semidarknesses | semiofficially |
| semiologically | semiporcelains |
| semiretirement | |
Note: These 11 14-letter words that start with 'semi' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with semic, semid, semin, semio, semip, semit, semia, semim, semis, semil, semif, semir, semig, semih, semiw, semib, semie, semiq, semiv, semiu, semiy.
5-letter words start with 'semi' (1)