There are 12 words that start with 'stale'.
| stale | staled | staler | 
| stales | stalely | stalest | 
| stalemate | staleness | stalemated | 
| stalemates | stalemating | stalenesses | 
Note: These 12 words that start with 'stale' are found from the USA & Canada version of the tournament Scrabble word list.