A pom-pom is a ball of threads which is used to decorate things such as hats or furniture. In the United States, cheerleaders wave large pom-poms at football matches.
...wide-brimmed hats with red pom-poms worn by the local girls.
pom-pom in British English
(ˈpɒmpɒm)
noun
an automatic rapid-firing, small-calibre cannon, esp a type of anti-aircraft cannon used in World War II
Also called: pompom
Word origin
C19: of imitative origin
pom-pom in American English
(ˈpɑmˌpɑm)
noun
any of several rapid-firing automatic weapons, as an automatic cannon of the Boer War or an antiaircraft cannon of WWII