1.AdjectiveWith its plug properly connected to the electric plug socket.
"Check if the television is plugged in."
2.AdjectiveFully aware; in a state of keeping up with current information about a topic; engaged wholeheartedly in a task or cause
"By subscribing to this magazine, you can stay plugged in to current issues.; My new boss is much more plugged in to the needs of his employees than my last boss.; Even the most plugged-in politics enthusiasts had a hard time understanding his oblique references."