There are 14 words that start with 'irres'.
| irresolute | irresoluble |
| irresistible | irresistibly |
| irresolutely | irresolution |
| irresolvable | irresponsive |
| irresolutions | irresponsible |
| irresponsibly | irresoluteness |
| irresponsibles | irresistibility |
Note: These 14 words that start with 'irres' are found from the USA & Canada version of the tournament Scrabble word list.