Idiom of The Day

http://upload.wikimedia.org/wikipedia/commons/thumb/7/7f/WWI_English_dud_bomb.JPG/220px-WWI_English_dud_bomb.JPG

damp squib (plural damp squibs)

1. A firework that fails to go off, due to wetting.
2. (idiomatic, by extension) Anything that doesn’t work properly, or fails to come up to expectations. 

from Wikitionary http://en.wiktionary.org/wiki/damp_squib