There are 3 12-letter words that start with 'bor'.
| boringnesses | borohydrides | borosilicate | 
Note: These 3 12-letter words that start with 'bor' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with bord, bore, bora, boro, borr, bori, bors, born, bort, bork, borb, borz.
4-letter words start with 'bor' (5)