Warlords in the Sengoku period signaled with a gourd-shaped war fan.
sumo referee's fan
The fan used by the gyōji (sumo referee) to indicate decisions and direct wrestlers. The word 軍配 alone is more common in sumo contexts.
The referee raised the umpire's fan high to indicate the winner.
fan-shaped emblem
A design or crest in the shape of the war fan, used as a family crest or decorative motif. Rare standalone use; usually part of a compound or description.
That family crest is shaped like a war fan.