A word which is used to describe someone, or something which is "all fart and no poo" (all chat and no action).
Steve: "When we go home lets funnel loads of booze"
Sally: "Steve mate you are Willbo In."
by Simon Rowe February 20, 2008
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Someone who bails on friends, possibly multiple times, when they want to see the hobbit because they have a massive pine cone in their twat.
Guy1&2: Wow, our newb of a friend bailed on the hobbit again.
Guy3: What a willbo!
by bigdickswagger December 27, 2014
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