gold medal; gold badge
Refers to a gold medal in competitions or a gold badge as a symbol of rank or achievement. The context determines whether it means medal or badge.
He won a gold medal at the Olympics.
その警官は金牌を制服に付けていた。
The police officer wore a gold badge on his uniform.
Compound of 金 (きん, 'gold') and 牌 (はい, 'medal' or 'badge'). The reading きんぱい is a standard on'yomi combination.