Squib is a British English word for firecrackers, things that explode when lit. Literally, a damp squib would be a wet firecracker, which of course would not light or be able to explode.
As a noun damp squib is listed in European dictionaries but not in some American. The term means an event that falls short of expectations or less impressive than anticipated. A good synonym is anticlimactic.
It should be noted that a squib has other meanings as well. A squib can be a short satirical essay, a physically weak person, a kick in sports that is deliberately made short, and a fluff or filler piece in a newspaper or new broadcast.
The promise of fireworks in the Turks and Caicos has now turned out to be nothing more than a grand wet squib worthy of grand old ladies smitten by delusions of grandeur. [Jamaica Observer]
However, it turned out to be a damp squib as the local leaders and even party’s own MLAs remained absent from the programme. [The Times of India]
Elections – even damp squibs like this one – yield characters and images that endure long after the polls have closed and the country has been condemned (or, ConDem-ed – if the status quo has its way). [Evening Standard]
The bottom line is Villa, and Lampard when he finally gets here, need to be healthy and firing on all cylinders to prevent their opening season dalliance turning into the dampest of squibs. [Daily Mail]