empty threat;  bluff;  paper tiger
 to threaten;  to menace;  to frighten (into doing)
 water-filled bamboo tube which clacks against a stone when emptied;  device for scaring birds from gardens
 threat;  bird-scaring device (scarecrow, gun, etc.)
 to threaten;  to menace;  to intimidate;  to startle;  to frighten;  to scare
 scarecrow;  bird rattle;  clapper