The Chinese word for piano is
钢琴

gāng qín

Chinese Definition

piano
1. 钢琴
2. 形容词. 平面
3. 形容词. 溫柔
4. 名词. 男性 (眾數 piani)
5. 名词. 樓層 (英國)
6. 名词. 钢琴
Components
钢
1. Simplified form of 鋼
琴
1. (musical instrument) qin (“Chinese zithers”), referring to any of several traditional Chinese musical instruments, most famously the guqin
2. (musical instrument) collective name for certain musical instruments, usually of string or keyboard types, such as piano, organ, violin, cello, huqin, accordion, harmonica, etc.
3. (musical instrument, specifically) piano (attn, zh, just Hong Kong?)
4. (Cantonese) yesterday