Well that doesn't tell you very much, geezzz, let me have a go at this one...
It means to be forced to do something extremely disagreeable.
One of my very dorky hobbies is etymology. That phrase comes from the 1812 war, basically an American soldier was hunting on British territory, he shouldn't have been. He shot a crow, which a British officer heard. The officer got ticked off, tricked the American out of his weapon, and then told him he couldn't have his weapon back until he took a bite out of the crow he shot as punishment. He took the bite, gross.. The British officer gave him his weapon back, but tricky tricky, the American then forced the officer to eat the rest of the crow, double gross.. Crows aren't good eat'n by the way, especially raw.