blow down

Short definition from Wiktionary

Verb

1. 1
   To knock over with an air current, most often wind.
2. 2
   To clean off from top to bottom with an air current from a compressed air hose.
3. 3
   Synonym of dirty down.
4. 4
   To kill (someone) with a gun.
5. 5
   To signal to someone by blowing into a whistle.