Meaning 1 ►▼
The lead dog is the first or lead dog of a pack of dogs pulling sleds over snow. This idiom is used particularly in northern places, such as Alaska, but not necessarily.
The most famous sled dog, with a statue honoring him in New York Central Park is Balto, who saved children's lives in 1933 by delivering medicine in Alaska.
Meaning 2 ►▼
to manage, lead
"Lead Dog's ability to manage this complex program is masterful." Will you be the lead dog on this project?
There have been sleddogs pulling dogsleds for at least a thousand years.