A merchant is a person who owns or runs a shop, or other business.
店主• The family was forced to live on credit from local merchants. 这家人不得不靠向当地的商家赊账过活。
Merchant seamen or ships are involved in carrying goods for trade.
商船的• There's been a big reduction in the size of the merchant fleet in recent years. 近年来商船队的数量大为缩减。