There are 19 words that start with 'secon'.
| second | seconal |
| seconde | secondi |
| secondo | seconds |
| seconals | seconded |
| seconder | secondes |
| secondly | secondary |
| seconders | seconding |
| secondhand | secondaries |
| secondarily | secondariness |
| secondarinesses | |
Note: These 19 words that start with 'secon' are found from the USA & Canada version of the tournament Scrabble word list.