Origin

The character 貿 combines two parts to represent trade. The bottom component is 貝, which means shell or precious item—shells were historically used as currency in East Asia, so this component came to represent anything of value or commercial goods. The top component 卯 serves as a sound hint, telling you roughly how to pronounce the character, rather than adding to its meaning. Together, the character's shape evolved to mean the exchange of valuable goods, which is the essence of trade.