Someone is very frightened. Drugs are often reffered to as "gear" and drug mules commonly swallow condoms containing drugs to get them through airport security. Some drug mules get scared and they poop out the drugs before passing through border control, thus the term "shit the gear" was born.
I rang him up to have a go at him and he shit the gear and hung up on me!
by Swasee April 4, 2016
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