In English, there is a big musical instrument called piano. Piano was created since the Middle Age. It consists of strings and hammers.
We know that English is originated from German. In German, piano is called Klavier. Why does it called Klavier? In English, there is another word - clavier to describe musical instrument - keyboard. It is same as the Clavier from French. Klavier may come from Latin (claves), clavile in Modern Latin. It is Klavír in Solvenian and Czech, Glasovir in Crotian. Clavier may mean key-bearer, key is clavis in Old Latin.
The name piano comes from pianoforte, same as Italian and Russian (Фортепиа́но) name. It is fortepian in Poland.
The most strange is that piano is Zongora in Hungarian. Why Zongora?