a guardian or defender against theft or illegal practices or waste
"she is the global watchdog for human rights abuses"
a guard dog
"The large watchdog barked loudly at every stranger who approached the front door."
To perform a function analogous to that of a watchdog; to guard and warn.
"The independent auditor acts as a financial watchdog, constantly reviewing company records to detect fraud and alert shareholders to any irregularities."
In plain English: To act as a watchdog is to keep an eye on something to make sure it stays safe and follows the rules.
"The government is watching dog every move to ensure fairness in the election results."
Usage: Use this verb primarily in formal or technical contexts when describing systems, organizations, or individuals that monitor compliance or safety. Avoid using it casually for simple observation, as the term implies an active role in preventing wrongdoing rather than just watching.
The word watchdog is formed by combining the words watch and dog to describe a guard animal that watches over property or livestock. It entered English as a literal description of this specific type of working dog rather than evolving from an older meaning.