D defs.my
Entry 1 sense Webster, 1913

Watchdog

/(wŏch"dŏg`)/ · Watch·dog · IPA /ˈwɑːt͡ʃˌdɑːɡ/
01 n. A dog kept to watch and guard premises or property, and to give notice of the approach of intruders.
  1. 1.
    A dog kept to watch and guard premises or property, and to give notice of the approach of intruders.