There are 14 words that start with 'underf'.
| underfed | underfur |
| underfeed | underflow |
| underfoot | underfund |
| underfurs | underfeeds |
| underflows | underfunds |
| underfunded | underfeeding |
| underfunding | underfinanced |
Note: These 14 words that start with 'underf' are found from the USA & Canada version of the tournament Scrabble word list.