shoo-in

The correct spelling is shoo-in, usually with a hyphen. It has been known in that spelling and with the meaning of a certain winner from the 1930s. It came from horse racing, where a shoo-in was the winner of a rigged race.

In turn that seems to have come from the verb shoo, meaning to drive a person or an animal in a given direction by making noises or gestures

These day's the term is associated with short odd's favourites in any sport
Australia are shoo-in's for the cricket world cup
by TheDaddy May 03, 2007
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Swallow Tattoos

Another meaning for them in the UK is that ex prisoners have swallows tattooed on their hands or wrists to prove they have served their time, as in they have done their bird.
Man A: They let you out then

Man B: Shows hands and says Yes I've done my bird

Man A: Oh yes you have swallow tattoos
by TheDaddy May 06, 2012
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