Older slang, used in cold weather to place emphasis on how extremely cold it is outdoors. cold it is outdoors. Damn, it's colder than a well-digger's ass!.
Could a well digger's ass be getting cold because they forgot to cover up their ass? Is a well digger's ass any colder than a witch's tit? Is a well.
This Slang page is designed to explain what the meaning of colder than a well digger's ass is. The slang word / phrase / acronym colder than a.