This is the 8444th most frequent German word.
kelpper
The German word "Kelpper" does not exist in standard German. You may mean "Klepper," which refers to an old or worn-out horse or, colloquially, a rickety object.
'Kelppern' as a plural noun refers to clappers, a type of traditional rattling instrument.
Die Kinder klappern mit ihren kleinen hölzernen Kelppern.
The children are rattling with their small wooden clappers.
'Kelppern' here functions again as an instrument used for producing sound, associated with cultural events.
Beim Umzug sahen wir Männer, die mit großen Kelppern Lärm machten.
During the parade, we saw men making noise with big clappers.
'Kelppern' as a historical or cultural object, showcasing its functional metaphorical use.