There are 2 12-letter words that start with 'roo'.
rootednesses | rootlessness | |
Note: These 2 12-letter words that start with 'roo' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with root, room, roof, roos, rook, roor, rood.
4-letter words start with 'roo' (5)