There are 13 words that start with 'roto'.
| roto | rotor | rotos | 
| rotors | rototill | rototills | 
| rotorcraft | rototilled | rototiller | 
| rotogravure | rototillers | rototilling | 
| rotogravures | ||
Note: These 13 words that start with 'roto' are found from the USA & Canada version of the tournament Scrabble word list.