Noun
(Australia) A coded warning used by men to alert each other that female guests ("ducks") are present ("on the pond"), so that for politeness they should moderate their language.
(baseball) Members of a batting order who are on base; baserunners.
There are two ducks on the pond for the cleanup hitter.
(Car Sales) There are customers arriving on the car lot.
Ducks on the pond. Who is up?