There are 13 words that start with 'rigo'.
| rigor | rigors |
| rigour | rigours |
| rigorism | rigorist |
| rigorous | rigorisms |
| rigorists | rigoristic |
| rigorously | rigorousness |
| rigorousnesses | |
Note: These 13 words that start with 'rigo' are found from the USA & Canada version of the tournament Scrabble word list.