There are 13 words that start with 'substi'.
| substitute | substituent |
| substituted | substitutes |
| substituents | substituting |
| substitution | substitutive |
| substitutable | substitutions |
| substitutional | substitutively |
| substitutionary | |
Note: These 13 words that start with 'substi' are found from the USA & Canada version of the tournament Scrabble word list.