There are 12 words that start with 'impen'.
| impend | impends |
| impended | impendent |
| impending | impenitent |
| impenitence | impenetrable |
| impenetrably | impenitences |
| impenitently | impenetrability |
Note: These 12 words that start with 'impen' are found from the USA & Canada version of the tournament Scrabble word list.