bolt
A streak of lightning is also called a lightning bolt.
1.21 gigawatts. Source: Doctor Emmitt Brown, Back to the Future
An angry streak is a temper.
A streak of lightning split the dark sky into half.
Fleet (of foot), swift (as a streak of lightning), are two possibilities.
won
A four letter word starting with the letter a is able.
A four letter word for 'in addition to' is also.
A four letter word for Seizures is moon
That Four-Letter Word was created in 2006.
Lard is a four letter word for grease.
It depends on what you mean by 'four letter word'. Thea has four letters, so yes it is. It is not a swear word, so it's not that kind of 'four letter word'.