blow·back 
(blōbăk′)
(blōbăk′)n.
1. The backpressure in an internal-combustion engine or a boiler.
2. Powder residue that is released upon automatic ejection of a spent cartridge or shell from a firearm.
3. Negative repercussions affecting a country whose government has undertaken a usually clandestine intelligence operation in another country.
- double-knit
- double negative
- doubleness
- double-park
- double-parker
- double play
- double pneumonia
- double possessive
- double-quick
- doubler
- double reed
- double-reed
- double refraction
- double replacement
- double reverse
- double rhyme
- double salt
- double sharp
- double-space
- doublespeak
- double standard
- double star
- double-stop
- doublet
- double-take