There are 21 words that start with 'defu'.
| defuel | defund | defuse |
| defuze | defuels | defunct |
| defunds | defused | defuser |
| defuses | defuzed | defuzes |
| defueled | defunded | defusers |
| defusing | defuzing | defueling |
| defuelled | defunding | defuelling |
Note: These 21 words that start with 'defu' are found from the USA & Canada version of the tournament Scrabble word list.