There are 17 words that start with 'iner'.
| inert | inerts | 
| inertia | inertly | 
| inerrant | inertiae | 
| inertial | inertias | 
| inerrable | inerrancy | 
| inertness | inertially | 
| inerrancies | inertnesses | 
| ineradicable | ineradicably | 
| ineradicability | |
Note: These 17 words that start with 'iner' are found from the USA & Canada version of the tournament Scrabble word list.