coon
for (or in) a coon's age a very long time. North American informal
1951William StyronLie Down in Darkness I haven't seen him in a coon's age.
a gone coon a person or thing in desperate straits or as good as dead. US informal
☞ Coon in these idioms is an informal abbreviation of raccoon. Raccoons were hunted for their fur, and a gone coon was one that had been cornered so that it could not escape.