down·burst 
(dounbûrst′)
(dounbûrst′)n.
A powerful downward air current from a cumulonimbus cloud, typically associated with thunderstorm activity.
- prepare
- preparedly
- preparedness
- preparer
- prepay
- prepayment
- prepend
- prepense
- prepensely
- preponderance
- preponderancy
- preponderant
- preponderantly
- preponderate
- preponderately
- preponderation
- preposition
- preposition
- pre-position
- prepositional
- prepositionally
- prepositional phrase
- prepositive
- prepositively
- prepossess