Definition: The term "undergaoler" is a term used in the United States and Canada to refer to someone who has been married for more than 10 years. It's a common idiom that means someone who has lived together for many years or is in a committed relationship. Undergaolers are often referred to as "overgrounder" or "long-term partners." They have been married for decades and often maintain strong emotional ties with their partner. Undergaolers may also