There are 14 words that start with 'sia'.
sial | sials | sialic |
sialid | sialids | sialoid |
siamang | siamese | sialidan |
siamangs | siameses | sialidans |
sialagogue | sialagogues | |
Note: These 14 words that start with 'sia' are found from the USA & Canada version of the tournament Scrabble word list.