Why would you want to ..say, boo to a goose?

Question

Why would you want to ..say, boo to a goose?

Answer 1

If they come at me, wings flapping and beaks squarking, I would not say, but , shout, " BOO."

Answer 2

I never said I would ! now leave me alone

Answer 3

Geese can be kind of aggressive.  You might want to say "boo" to it so it will go away and not peck at you!

Someone who "wouldn't say boo to a goose" is considered very timid.