There are 13 words that start with 'streak'.
| streak | streaks | 
| streaky | streaked | 
| streaker | streakers | 
| streakier | streakily | 
| streaking | streakiest | 
| streakings | streakiness | 
| streakinesses | |
Note: These 13 words that start with 'streak' are found from the USA & Canada version of the tournament Scrabble word list.