Quick Definition: A number that a woman gives out with no intention of ever calling back.
Wood essentially is a useless number because the number was given without the foundations of attraction or rapport. Sometimes this is the result of the PUA playing weak game, and sometimes the wood is just the woman’s way of politely blowing off the PUA.
It is sometimes possible to play great text game and revive a dead number, or send mass text messages out to all of one’s wooden numbers in the hopes of getting a response, but usually it is a lost cause. The best thing to do is to frame the wood as a positive learning experience, and move on.