There are 14 words that start with 'semia'.
| semiarid | semiangle |
| semiangles | semiannual |
| semiaquatic | semiaridity |
| semiabstract | semiannually |
| semiarboreal | semiaridities |
| semiautomatic | semiautomatics |
| semiautonomous | semiabstraction |
Note: These 14 words that start with 'semia' are found from the USA & Canada version of the tournament Scrabble word list.