I. ˈ ̷ ̷ˌ ̷ ̷ noun
Usage: often attributive
Etymology: watch (II) + dog
1. : a dog kept to guard against trespassers or thieves
2. : one that guards against loss, waste, theft, or undesirable practices
should deal with its responsibilities in this matter as a watchdog on behalf of the nation as a whole — Stephen King-Hall
II. transitive verb
: to act as a watchdog for
opposed tax funds for television as part of its role of watchdogging the public purse — Richard Lewis