There are 20 9-letter words that start with 'sum'.
| summaries | summarily | summarise |
| summarist | summarize | summating |
| summation | summative | summerier |
| summering | summerset | summiteer |
| summiting | summoners | summoning |
| summonsed | summonses | sumptuary |
| sumptuous | sumpweeds | |
Note: These 20 9-letter words that start with 'sum' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with summ, sump, suma, sumo, suml, sums.
4-letter words start with 'sum' (3)